U.S. Women's Olympic Team for Rio

With the opening ceremony of the 2016 Summer Olympics in Rio de Janeiro just one day away, there is much anticipation among volleyball fans regarding the various competitions within the sport. Kerri Walsh will be seeking her fourth straight gold medal in women's beach volleyball (this time partnered with April Ross, rather than longtime partner Misty May), but we'll save that topic for another day.

The present entry is about the U.S. women's indoor team, which is seeking its first Olympic gold medal in program history. After a shocking setback to Brazil in the final of the 2012 London Olympics, the U.S. women won their first major international title at the 2014 World Championships. The Americans then took third at the 2015 World Cup.

There appear to be several top contenders on the Rio hardwood, besides the U.S., including home-team Brazil, China, Serbia, and Russia. Don't be surprised to see semifinal and final matches coming down to decisive fifth games!

The following chart presents the U.S. women's roster (obtained here), with a focus on the players' collegiate success in making American Volleyball Coaches Association (AVCA) All-America teams.

Player (Position)	College	All-America Teams (AVCA)
Rachael Adams (Middle)	Texas	1st, 2011; 1st, 2010
Foluke Akinradewo (Middle)	Stanford	1st, 2008; 1st, 2007; 1st, 2006; 2nd, 2005
Kayla Banwarth (Libero)	Nebraska	---
Christa (Harmotto) Dietzen (Middle)	Penn State	1st, 2008; 1st, 2007; 2nd, 2006; HM, 2005
Alisha Glass (Setter)	Penn State	1st, 2009; 1st, 2008; 2nd, 2007
Kim Hill (Outside Hitter/left)	Pepperdine	1st, 2011; HM, 2010; HM, 2009
Jordan Larson (Outside Hitter/left)	Nebraska	1st, 2008; 3rd, 2007; 1st, 2006
Carli Lloyd (Setter)	Cal	1st, 2010; 2nd, 2009; 2nd, 2008
Karsta Lowe (Opposite/right)	UCLA	1st, 2014; HM, 2013
Kelly Murphy (Opposite/right)	Florida	1st, 2011; 1st, 2010; 2nd, 2009; 3rd, 2008
Kelsey Robinson (Outside Hitter/left)	Nebraska	1st, 2013; HM, 2012*; 2nd, 2011*
Courtney Thompson (Setter)	Washington	1st, 2006; 1st, 2005; 1st, 2004

*While playing for Tennessee, before transferring to Nebraska.

Foluke Akinradewo is the leading hitter in the middle, in my view, based partly on the 2015 World Cup. Former Minnesota Golden Gopher Tori Dixon, with whom I've long been impressed, might have been among the team's middle corps, but suffered an ACL injury earlier in the year.

I'm least familiar with the outside (left-side) hitters. Kim Hill played for Pepperdine, which is not in a conference I concentrate on. Jordan Larson's career goes back a ways, only partially overlapping with my time operating this blog. Kelsey Robinson, in her one year at Nebraska (2013) after transferring from Tennessee, hit .318 while taking a very high 29.2 percent (1206/4132) of the Cornhuskers' swings that year.

This Volleyball Magazine article from back in February details the intense competition between Kelly Murphy, Karsta Lowe and Nicole Fawcett for what was anticipated (and indeed turned out) to be two openings for opposite/right-side hitters on the roster. (The term "opposite" comes from being opposite the setter in the rotation.)

Lowe did not perform that well in the 2015 World Cup, but improved dramatically in the January 2016 NORCECA regional qualifying tournament in Lincoln, Nebraska. Quoting from the above-linked Volleyball Magazine article:

"Teamed with [setter Courtney] Thompson in Lincoln, Lowe tallied a combined 22 kills and not a single hitting error in 34 attempts (.647) over less than 10 serving rotations."

Fawcett was named MVP of the NORCECA tournament, but ended up being the odd-woman-out for the Olympic team.

Joining Thompson in the setting ranks are Alisha Glass, key to one of Penn State's run of national titles, and Carli Lloyd (not to be confused with the U.S. soccer player of the same name). In 2010, Lloyd led Cal to the national final and was voted national Player of the Year. I once wrote of Lloyd that "during her senior campaign [in 2010, she] not only ran the high-powered Golden Bear offense, but also hit a respectable .265 on 283 tries (7% of the team's attempts) and contributed 1.08 blocks/set. (... I've come to regard an average of 1.00 or greater blocks/set as a marker for excellence in blocking.)"

All players on the U.S. roster, except former Nebraska libero Kayla Banwarth, earned at least one AVCA first-team accolade, with seven players receiving first-team honors in multiple-years.** Nor did Banwarth play extensively in overseas professional leagues. Her college coach John Cook was quoted as follows in the Des Moines Register:

“What’s really amazing, though, is she stayed with it, without really having much of a pro career," Cook said. "She’s just continued to hone her skills, training in Anaheim (Calif.), training with (U.S. coach) Karch Kiraly and training some days by herself.”

As I reported here, Kiraly gave a forum at Texas Tech University in March 2015, where he revealed many aspects of his philosophical approach to coaching.

We'll continue to track the U.S. women, as they progress through the competition in Rio.

---
**For each of the last several seasons, AVCA has been bestowing first-team honors to 14 players, so being placed on the first team is more like being on a hypothetical "best roster" rather than "best starting unit."

NCAA Men's Tourney: If BYU and UCLA Meet in Final, Bruins' Serving Could Be Crucial

We're now down to the Final Four of men's NCAA volleyball, with two semifinal matches tonight -- No. 1 seed BYU vs. No. 4 Long Beach State, and No. 2 seed UCLA vs. No. 3 Ohio State -- and the final on Saturday (link to bracket). In the event of a BYU-UCLA final, which is no certainty, my preview below will be useful. If not, it will have been purely an academic exercise.

BYU and UCLA have played three times this season, in a pair of regular-season matches in Los Angeles (here and here) and in the MPSF conference-tournament final in Provo. The Cougars have taken all three contests, each in four games. In each of these matches, Bruin serving errors have played a seemingly large role in determining the outcome. UCLA committed 15 service errors in the first match, 20 in the second, and 27 in the third. I find this unbelievable, but in the three matches combined, the Bruins missed one-quarter of all their serve attempts (62 misses on 246 serves, which is .252)! (These and other statistics appear in a table below, which you can click to enlarge.)

Of course, a strategy of "just get it in" would help the Bruins only modestly. BYU won nearly two-thirds (.648) of the rallies on UCLA's serve (i.e., when the serve was non-terminal, not an ace or error). If the Bruins floated a bunch of soft, unchallenging serves the Cougars' way, BYU's side-out rate on rallies would almost certainly go up by a sizable amount. The other side of the argument, though, would be that UCLA won zero points on all its missed serves and picking up even a few extra points by winning rallies on less-aggressive serves could be important in a close match.

Tristan Burton and Scott Powers published a thoughtful and sophisticated analysis of the serving-aggressiveness trade-off -- more-effective serves vs. more errors -- in 2015 in the Journal of Quantitative Analysis in Sports (summary). As these authors note, "a balance among [service-ace fraction, service-error fraction] and opponent offensive ability must be considered in order to guide service strategy" (p. 3). Using calculus and other advanced mathematics (e.g., the "Newton-Raphson solution"), Burton and Powers derive graphical displays for determining which players need to serve more or less aggressively. Lacking the volume of data and the brainpower* necessary to apply Burton and Powers' formulations in full, I came up with my own analysis of UCLA's serving vs. BYU, which made intuitive sense to me.

Using play-by-play sheets from the three BYU-UCLA matches (available via BYU's schedule page, by clicking on "Box" for a given match, and then "Play-By-Play"), I recorded the outcome of every serve for each of UCLA's eight main servers (listed in the table above). A serve could result in one of four outcomes: an ace or an error (both considered "terminal" outcomes), a rally (i.e., after a non-terminal serve) won by UCLA, and a rally won by BYU.

Not much was going on with UCLA ace serves (only 18 total in the three matches; 8, 9, and 1 by match chronologically). I therefore focused on service errors. For each of the eight Bruin players, I computed his service-error percentage (number of errors divided by total number of serves) and the percentage of time on that player's serve that UCLA won a rally after a non-terminal serve.

To the extent aggressive serving results in both service errors and (when the serve goes in but does not produce an ace) the receiving team being taken out-of-system in running its offense, we should find a positive correlation between UCLA players' service-error percentage and percentage of rallies won by UCLA. Indeed, we do, as shown in the following graph.

For readers with statistical training, the correlation coefficient (r) =  .52. This is a fairly large correlation, but caution is warranted due to the small sample size of 8 players. (Free plotting software is available here.) A couple of players exemplify the trend. Oliver Martin committed only 1 error on 29 total serves vs. BYU during the season (3.4%), but his (apparently) low-risk serving also was easy for the Cougars to field, so that the Bruins won fewer than one-third of the rallies on Martin's serve. At the other extreme, Jackson Bantle had a much higher rate of service errors, committing them 28.6 percent of the time, but UCLA won 44.4 percent of rallies on his serve.

I'll leave the precise optimization of service aggressiveness to Burton and Powers. If you want to determine how risky to be in your serving, taking account of the opponent's ability to launch its offense, you should look at their article. What I've concluded from my little exercise is that UCLA seems to have a good reason to serve aggressively. However, the Bruins' service-error rate does seem excessively high.

UPDATE: A BYU-UCLA match-up in the NCAA men's final never happened, as Ohio State beat the Bruins in a tense five-game semifinal match. The Buckeyes survived three match-points in the decisive game, before winning it 18-16. OSU continued its momentum into the championship match, shockingly sweeping BYU. The Buckeyes outhit the Cougars, .374-.296; not only that, OSU took 20 more attack attempts than did BYU, 91-71, indicative of the Cougars' passing difficulties (box score). BYU's award-winning right-side (opposite) hitter Ben Patch, hitting .383 entering the NCAA tourney, performed well-below that in the final, hitting .091 on 10 kills and 8 errors in 22 swings.

---
*I did take a year of calculus as a college freshman 35 years ago and I occasionally watch calculus lectures online to retain as much of it as I can. However, I feel nowhere near confident enough to conduct the analyses reported by Burton and Powers.

Huskers Sweep Horns to Win NCAA Women's Title

Playing in Omaha, not far from the school's Lincoln campus, the University of Nebraska swept the University of Texas, 25-23, 25-23, 25-21, to win the Cornhusker program's fourth NCAA title (the third under current coach John Cook) on Saturday, December 19. Here's a link to the box score and play-by-play sheet.

As shown in the following graph, Nebraska outhit Texas by a substantial margin in each game. Yet the games were tight (especially the first two). The Huskers were called for three "assist errors" (perhaps the setter backing into the net or contacting the ball above the net when starting out from the back row) and one ball-handling error for the match, whereas the Longhorns were called for none of either, thus giving UT a four-point advantage in that department and negating some of NU's hitting edge.

Pacing the Husker hitting attack were outside-hitter Mikaela Foecke (.385 percentage, based on 19 kills and 4 errors, on 39 swings) and middles Amber Rolfzen (.625, 10-0-16) and Cecilia Hall  (.500, 7-2-10). Hall's take on the situation, as reported in this Lincoln Journal-Star article, was that, “Mikaela just pulled their block away, and that made it easy to get kills,”

Nebraska called on its middles slightly less than did Texas, though. Husker middles attempted 26 out of the team's total 119 hitting attempts (21.8%), whereas Longhorn middles took 29 of the team's total 121 swings (24.0%).

The following ESPN graphic (of which I took a screenshot) shows the Longhorns' serve-receipt woes, which forced setter Chloe Collins to frequently deliver her sets from non-advantageous spots on the floor (shown as the dots, within the area within the imaginary blue arc being optimal). As television analyst Karch Kiraly put it, Collins often had to "put on her track shoes." For whatever reason, ESPN couldn't get Nebraska's spatial statistics to show up.

Of UT's two leading middles, Molly McCage (.429, 7-1-14) acquitted herself well, but Chiaka Ogbogu had as many hitting errors as kills (4 each) on 15 attempts, yielding a .000 percentage. One Longhorn who was not fazed by the team's erratic passing was frosh outside-hitter Yaasmeen Bedart-Ghani. In the championship match, she hit .500 (11-1-20), following up on a .583 (15-1-24) performance in the semifinal against Minnesota.

***

My Conference-Adjusted Combined Offensive-Defensive (CACOD) forecasting tool once again did well, even though none of the top-three-ranked teams on the CACOD (Washington, USC, and Penn State) made the Final Four. For each of the tournament's 63 matches, the team with the higher CACOD won 51 times and lost 12.

As shown in this summary of the VolleyTalk discussion board's Pick the Winner contest, someone correctly picked the winners of 54 matches. This is particularly impressive, in light of the following procedural aspect:

The PTW contest results... are based on the teams chosen before any of the games have been played and are not updated to show the actual teams playing in rounds subsequent to the first one. So if a high seed and consensus final four team is eliminated in the first round, anyone who picked that team for the following rounds automatically loses. On the other hand, RichKern... calculate[s] results a different way. RK looks at each succeeding game after the first round on a fresh basis to determine a win or loss based upon the last poll rankings for the two actual teams in each such game... 

Like RichKern, I use the CACOD to make "fresh" picks at the beginning of each new round (e.g., round of 64, round of 32, round of 16, etc.), using the actual teams in a given match.

NCAA Women's Preview 2015

I didn't write much during the regular season, but I'm ready to go for the NCAA women's tournament. I have once again produced my Conference-Adjusted Combined Offensive-Defensive (CACOD) metric, the methodology of which is explained here. The heart of the CACOD is the ratio of a team's own hitting percentage to the hitting percentage allowed to opponents. The 64 NCAA teams are ranked below on the CACOD (unless you have amazing eyesight, you'll want to click on the images to enlarge them).

The principle is simple: Whenever two teams play, the one with the higher CACOD would be favored to win. The CACOD's success rate in predicting winners of NCAA women's tournament matches has been right up there with other forecasting tools such as Pablo, Massey/Elo, and RK (see here and here). Last year, the CACOD foresaw BYU's run of upsets in the NCAA tourney.

The Washington Huskies (28-2) come out No. 1 on the CACOD, with a clear margin over the next-closest teams. U-Dub also finished the season atop the AVCA coaches' poll, but received only a No. 5 seed from the NCAA. The Huskies' only losses were at USC (3-1) and at Stanford (3-2).

The No. 1 tournament seed is USC, which got off to a surprisingly torrid start this season, before losing to Washington and UCLA in the second half of conference play. A key to the Trojans' success this season was their mettle in road five-game matches. Four times (at Stanford, at Colorado, at Washington State, and at Arizona State), 'SC prevailed in five. However, in the final days of the season, UCLA took a five-setter from USC on the Trojans' home floor.

Looking over which teams have had the highest CACOD each year (since its introduction in 2011), I find that Washington has the highest score for a yearly leader of any school not named Penn State:

Penn State (2014) -- 3.09
Penn State (2013) -- 2.91
Penn State (2012) -- 2.85
Washington (2015) -- 2.67
Nebraska (2011) -- 2.29

That's all for now. I'll continue to comment on tournament results and the CACOD as "December Madness" progresses.

USC Continues Undefeated; Penn State in Uncharacteristic Collapse vs. Nebraska

USC, having displayed an amazing ability to prevail in tight games and matches thus far, will almost certainly be ranked No. 1 in the next national poll. Now 16-0, the Trojans have staked their claim to the top ranking with wins at Stanford last Sunday (26-24, 19-25, 20-25, 25-17, 15-13) and at home vs. Washington today (25-16, 22-25, 25-21, 33-31).

This wasn't supposed to happen, at least according to the preseason AVCA poll, which had USC at No. 22. In fairness to the voters, the Trojans had were coming off a weak 16-16 record last season and were losing two transfer players, Ebony Nwanebu (to Texas) and Lauryn Gillis (to Wisconsin). It should be noted, however, that Nwanebu and Gillis did not put up great hitting percentages for the Trojans a year ago (.226 and .174, respectively).

Thus far in 2015, USC is playing lights-out both offensively and defensively, in terms of hitting percentage (you may click on the following graph to enlarge it).

The Trojan offense is led by a trio of upper-year players. As shown in the following table, senior outside-hitter Samantha Bricio is taking a huge number of attack attempts and hitting at an excellent .323 clip, with middle-blockers Alicia Ogoms and Elise Ruddins hitting at .419 and .412, respectively. (OH is considered a more difficult position than MB for attaining a high hitting percentage, as an OH tends to get a higher number of "desperation" sets when a team is out of system.)

Player (Position)	Year	Hitting Pct.	Spike Att.
Alicia Ogoms (MB)	Sr.	.419	198
Elise Ruddins (MB)	Jr.	.412	148
Samantha Bricio (OH)	Sr.	.323	609
Alyse Ford (OH)	Fr.	.285	316
B. Abercrombie (OPP)	So.	.247	304
Baylee Johnson (S)	Fr.	.190	147

***

After crushing Nebraska in the first game, 25-12 and eking out a 26-24 win in Game 2, top-ranked and previously undefeated Penn State not only lost the next three, but never really threatened to close out the match. The Cornhuskers' winning margins in these final three games were 25-14, 25-20, and 15-11 (box score).

While Nebraska hit pretty well in the third and fifth games, the big story in my view was the decline in Penn State's hitting. In the final three games, the Nittany Lions hit .059, .083, and .100. I don't know the last time Penn State hit .100 or below in three games of the same match, but I would imagine it was a long time ago!

Nebraska couldn't maintain the momentum from its win at Penn State, however, losing in five the next night at Ohio State. The Huskers are now 12-2.

'15 Women's World Cup Ends, College Play Begins

Needing a top-two finish at the FIVB World Cup in Japan to qualify for next year's Olympic Games in Rio de Janiero, the U.S. women took third. China (first) and Serbia (second) advance to Rio. (Brazil is automatically in the Olympics as host country, so per FIVB policy, did not participate in the World Cup.)

The World Cup uses a round-robin format exclusively, with no elimination rounds (i.e., seminfinals, finals). Under this format, the U.S. finished 9-2, with losses to Serbia (in five games) and Russia (in three). Final standings are shown here, with the U.S. match log shown here.

The U.S. still has another opportunity to qualify for the Olympics through competition at the North, Central America and Caribbean Volleyball Confederation (NORCECA) level.

Below, I've graphed how U.S. attackers performed against top competition (China, Serbia, fourth-place Russia, and fifth-place Japan). For each player, only matches in which she took at least 10 swings are shown. (Unless you have amazing vision, you'll want to click on the graphic to enlarge it.)

The three most consistent offensive threats for the U.S. (in terms of hitting percentage, at least) appeared to be Foluke Akinradewo (middle-blocker), Nicole Fawcett (opposite), and to a somewhat lesser extent, Jordan Larson-Burbach (outside-hitter). These are three of the more experienced players on the U.S. roster.

***

As the World Cup was winding down, the U.S. women's collegiate season was getting underway. This past weekend saw a match-up of No. 1 Penn State and No. 2 Stanford (won by the Nittany Lions), and between No. 3 Texas and No. 4 Florida (won by the Gators).

In Austin, three Florida players -- Ziva Recek (9-0-16, .562), Mackenzie Dagostino (5-0-10, .500), and Rhamat Alhassan (13-1-25, .480) -- committed only one hitting error amongst themselves.

In State College, Penn State featured an impressive trio of its own: Aiyana Whitney (13-2-25, .440), Haleigh Washington (12-2-19, .526), and Megan Courtney (11-1-25, .400).

"Volleyball Tracking" Site Provides Micro-Level Data

Over on a discussion thread at VolleyTalk, I learned of a service called Volleyball Tracking. One can find online a sample report of a match, providing information on such statistics as serve speeds, total number of meters run by each player during a match, and set-to-spike times (in fractions of a second). In addition, the report includes heat-maps and vector-type serve-trajectory diagrams. A separate Volleyball Tracking webpage shows animation of player movements on points during the match.