Wednesday, December 25, 2013

NCAA Women's Final: Penn State Dominates Early, Hangs on Rest of the Way vs. Wisconsin for Title

Penn State won its sixth NCAA women's volleyball title in school history last Saturday night, stopping an amazingly tenacious Wisconsin Badger squad in four games, 25-19, 26-24, 20-25, 25-23.  The Badgers had lost 3-0 to the Nittany Lions both times in Big 10 play this season (although there were some tight "deuce games" in there). Other Wisconsin losses during conference play (e.g., 0-3 to Michigan and 1-3 to Illinois, both in Madison) made it seem even less likely the Badgers would make it to -- and seriously contest -- the national championship match. But, two nights after shocking defending champion Texas, Wisconsin most certainly did make a serious run for the national title!

Penn State dominated for a stretch, spanning roughly the middle of Game 1 to the middle of Game 2 (discussed below). Once Wisconsin woke up in Game 2, however, the Badgers outplayed the Nittany Lions for most of the rest of the evening. PSU seemed to struggle to play on even terms with Wisconsin from the middle of Game 2 onward. Still, the Nittany Lions came through with brief flourishes at the end of Games 2 and 4, which, coupled with Badger miscues at the same time, proved enough for a Penn State championship.

Based on the play-by-play sheet from the championship match, I created the following graphic of the scoring sequences in the four games (Wisconsin in red, Penn State in blue). Unless you have some amazing eyesight, you'll want to click on the graphic to enlarge it.


The Nittany Lions' dominant stretch, to which I alluded above, began right after Wisconsin had cut PSU's Game-1 lead to 16-15. The Nittany Lions proceeded to close out the opening game 25-19 and then dart off to an 11-5 lead in Game 2. During this run, Penn State hit a sizzling .538 according to my unofficial tally (14 kills with no attack errors, on 26 swings).

At this point, it looked as though the Nittany Lions might waltz off with the national title as easily as they had dispatched the hometown Washington Huskies in Thursday night's semifinal romp (25-14, 25-13, 25-16). Seemingly out of nowhere, however, Wisconsin rebounded from its 11-5 Game-2 deficit to outscore Penn State 14-6 and take a 19-17 lead. The Badgers maintained the upper hand to hold a game-point at 24-23, but a missed serve (coming on the heels of a missed Wisconsin serve while holding a 23-22 lead), kept the Lions alive at 24-all. Back-to-back kills by PSU's Ariel Scott then put Game 2 in the Lions' column, 26-24. Scott, a senior right-side hitter, was Penn State's most effective attacker from the "pins" (outside, by the antennae that define the width of the court), with a .294 evening (21 kills and 6 errors, on 51 attempts).

One likely factor in Wisconsin's turnaround -- and near-win -- in Game 2 was the disappearance of the Penn State block. The Nittany Lions took a 2-1 lead in Game 2 on a stuff by senior middle-blocker Katie Slay and then did not score again via the block until well into Game 3, when Nia Grant and Megan Courtney teamed up to give the Lions a 9-8 lead. (Wisconsin outblocked Penn State on the evening, 14 to 9.) The Badgers pulled off a 6-0 run in Game 3 to take a 17-12 lead and closed things out 25-20.

Jumping ahead to Game 4, Wisconsin used a pair of 4-0 runs to help take a 23-20 lead, and a decisive fifth game seemed all but certain. However, reprising their late comeback against Stanford in the regional finals, the Nittany Lions scored the final five points against the Badgers to take Game 4 (25-23), the match, and the championship. PSU setter Micha Hancock put her signature on the win with two service aces down the stretch.

Two other trends defined the match in my mind. First was the "Battle of the Middles," featuring Penn State's Slay and Wisconsin junior Dominique Thompson. When in the front row, Slay typically remains in the center to hit quick sets. Thompson, in contrast, frequently runs the slide play, in which a middle hitter darts out to the right-hand side in an attempt to hit against one blocker instead of two. Thompson, who ended up hitting .314 on the evening (16-5-35), compiled four kills in rapid succession on slide plays in Game 3, as the Badgers rallied from a 5-3 deficit to even the score at 7-7. Here's a graph of Slay and Thompson's kills per game.



Slay's hitting line for the match was an excellent .481 (14-1-27), helped by an almost complete absence of hitting errors. As the graph shows, however, 10 of her 14 kills occurred in the first two games (6 in Game 1 and 4 in Game 2). Thompson, in contrast, appeared to peak in Games 2 and 3, with only a single kill in Game 4.

The second trend that struck me was how, relative to the Nittany Lions, the Badgers didn't even obtain that many of their points from kills. Instead, using what I call a "grind-it-out" style, Wisconsin kept a lot of balls alive and capitalized on Penn State errors of various kinds (e.g., service errors; ball-handling errors; and hitting errors, which include balls spiked out of bounds and those blocked back to the floor on the hitter's side of the court for an immediate defensive point). In pie-chart form, the following graphs (again, which you can click to enlarge) show how each team got its points (the Lions scored a total of 96 points on the evening, the Badgers, 91).


The Badgers amassed 45 kills*, accounting for just under half of their 91 total points. The Nittany Lions, in contrast, pounded out 61 kills, accounting for nearly two-thirds of their 96 points. However, Wisconsin received larger shares of its respective points than did Penn State from blocking, opponent spikes hit out of bounds (calculated from the box score as opponent hitting errors minus a team's own blocks), opponent serving errors, and opponent ball-handling errors.

Most observers probably would not have expected this relatively high rate of errors from a senior- and junior-laden Penn State squad. Nevertheless, the Nittany Lions' moxie and offensive firepower were enough to earn them yet another crown.

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*The box score shows 46 kills for Wisconsin and 62 for Penn State. However, it also shows 1 blocking error for each team, which typically involves a blocker touching the net. According to AVCA scorekeeping guidelines, “if there is a block error, there MUST be a kill for the other team.” In other words, once a net-violation or other blocking error is called, the play must also have a kill recorded, as a technical requirement. To prevent the disposition of any play from being counted twice, therefore, I counted block errors without their accompanying kills. The AVCA guidelines ("Making Volleyball Statistics Simple") are linked in the right-hand column of this page.

Wednesday, December 18, 2013

Statistical Notes Heading into Women's Final Four (2013)

With this year's NCAA women's Final Four getting underway Thursday night in Seattle, today's posting offers some statistical observations. The two semifinal match-ups feature defending champion Texas vs. upstart Wisconsin, and Penn State vs. hometown favorite Washington.

Wisconsin, a one-time power that had missed the NCAA tourney from 2008 through 2012, is now back in an ascendant mode under new coach Kelly Sheffield. Seeded 12th nationally, the Badgers benefited in their part of the bracket from the fact that SEC teams Missouri (No. 4 seed) and Florida (No. 5 seed) were Paper Tigers and Gators, respectively. Having said that, Wisconsin may be the kind of team that can give Texas a tough match (like Michigan in last year's semifinal).

A year ago, I developed a statistic that attempts to measure teams' "grind-it-out" tendencies. To me a grind-it-out team is one that lacks spikers with pulverizing power, but digs opponents' attacks well and avoids hitting errors of its own. A grind-it-out team may need two or more spike attempts within the same rally to finally win a point. The calculation of a team's grind-it-out statistic is quite simple: the number of spike attempts it takes in a match, divided by total points in the match (to control for match length). A power team, which puts away a lot of spikes immediately, will (usually) have few total swings in a match and thus a low grind-it-out score. Last year, Michigan scored highly on the grind-it-out measure.

This year's Badgers, who ranked sixth in the Big 10 in hitting percentage, but first in digs, seem to me to be a grind-it-out team. Below are my calculations of every team's match-specific grind-it-out statistics within the Sweet Sixteen and Elite Eight. Indeed, Wisconsin is the only team to exceed .90 in both of its matches (vs. Florida State; and Purdue). It must be noted that even a power team, such as Penn State, which led the Big 10 in hitting percentage, can find itself in grind-it-out matches, as the Nittany Lions did in their very tight regional final against Stanford. Similarly, Washington (vs. Kansas) and USC (vs. BYU) didn't need many swings in their respective regional semifinals, but sure did in their epic regional final. Wisconsin is the only team shown below to record high grind-it-out numbers while winning its matches relatively easily (each 3-1).

"GRIND-IT-OUT" PROPENSITIES

Neb (vs. Tex): 139 total points, Neb 142 TA (1.02)
PennSt (vs. Stan): 217 total points, PSU 219 TA (1.01)
Wash (vs. USC): 224 total points, Wash 217 TA (.97)
Min (vs. Stan): 149 total points, Min 142 TA (.95)
Wisc (vs. FlaSt): 175 total points, Wisc 165 TA (.94)
Wisc (vs. Pur): 184 total points, Wisc 172 TA (.93)
MichSt (vs. PennSt): 179 total points, MSU 167 TA (.93)
USC (vs. Wash): 224 total points, USC 209 TA (.93)
Amer (vs. Tex): 175 total points, Amer 159 TA (.91)

USD (vs. Neb):  140 total points, USD 125 TA (.89)
Tex (vs. Neb): 139 total points, Tex 124 TA (.89)
Stan (vs. Min): 149 total points, Stan 132 TA (.89)
BYU (vs. USC): 187 total points, BYU 166 TA (.89)
Pur (vs. Wis): 184 total points, Pur 162 TA (.88)
Tex (vs. Amer): 175 total points, Tex 148 TA (.85)
FlaSt (vs. Wisc): 175 total points, FSU 149 TA (.85)
PennSt (vs. MichSt): 179 total points, PSU 152 TA (.85)
Kan (vs. Wash): 131 total points, Kan 110 TA (.84)
USC (vs. BYU): 187 total points,  USC 155 TA (.83)
Stan (vs. PennSt): 217 total points, Stan 181 TA (.83)
Ill (vs. Pur): 143 total points, Ill 117 TA (.82)
Pur (vs. Ill): 143 total points, Pur 116 TA (.81)
Neb (vs. USD):  140 total points, Neb 114 TA (.81)

Wash (vs. Kan): 131 total points, Wash 96 TA (.73)

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Serving may also play a large role in determining the next national champion. On Monday's broadcast of "The Net Live," a volleyball talk show on Internet radio, the coaches of the Final Four teams were each interviewed (archived broadcasts can be accessed via the link to Volleyball Magazine in the right-hand column of this page). Penn State's Russ Rose, a noted statistical guru, pointed out that Washington, his team's Thursday night opponent, achieved an unusually strong ratio this year of aces to service errors. Serving aggressively will usually drive up both a team's ace and error numbers, but the Huskies managed to keep their miscues relatively in check. Here are the ratios, as I calculated them for each Final Four team.

Team................Aces..........Service Errors...............Ratio

Washington.......201........................221....................... .91

Penn State........152........................243....................... .63

Texas...............117........................226....................... .52

Wisconsin.........162........................355....................... .46

Volleyblog Seattle has a more elaborate look at the Final Four teams' serving prospects.

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Finally, I wanted to acknowledge the amazing performance of USC frosh right-side hitter Ebony Nwanebu against Washington. Nwanebu recorded 30 kills and no errors on 53 spike attempts, for a .566 hitting percentage (box score). She took 53 swings and never once hit the ball out of bounds or into the net, or had the Huskies block the ball back onto the Trojan side of the floor for a point. Each time Nwanebu was set, she either got a kill or the ball was kept in play by U-Dub. Such a high hitting percentage on that many swings is quite unusual.

Thursday, December 5, 2013

My Simple Prediction Equation for the NCAA Women's Tourney

Two years ago, I created a very simple prediction equation for the NCAA women's tournament. Each team gets its own value on the predictive measure. To calculate it, you take a team's overall hitting percentage at the end of the regular season and divide it by the hitting percentage the team allowed its opponents (in the aggregate). The result is then multiplied by an adjustment factor for conference strength, as shown here. For any match in the NCAA tourney, the team with the higher value on my measure would be expected to win.

In both 2012 and 2011, my formula did about as well as other, more complicated ranking formulas. I'm not going to do a full-scale analysis for this year's bracket, but I wanted to mention the formula and provide some sample calculations, in case anyone wanted to compute a score this week for his or her favorite team. The necessary information should be available from the volleyball page of a given school's athletics website. Here are 2013 values for my equation for this year's top eight seeded teams...

1. Texas........... (.295/.174) (1.20) = 2.03
2. Penn State.... (.312/.134) (1.25) = 2.91
3. Washington... (.282/.192) (1.25) = 1.84
4. Missouri........ (.362/.170) (1.00) = 2.13
5. Florida...........(.331/.166) (1.00) = 1.99
6. USC............. (.281/.178) (1.25) = 1.97
7. Stanford........ (.313/.170) (1.25) = 2.30
8. Nebraska...... (.271/.185) (1.25) = 1.83

The median value on my measure (i.e., the value that half the teams score above and half the teams score below) tends to be around 1.40. Most teams making the Final Four in the previous two years have scored above 1.80 on my measure, so that is a benchmark for gauging a team's chances this year of making the Final Four. Last year, NCAA champion Texas had a value of 2.19, runner-up Oregon was at 1.82, and semifinal losers Michigan and Penn State had values of 1.47 and 2.85, respectively. In 2011, national champion UCLA clocked in at 1.94, runner-up Illinois scored 1.81, and semifinal losers Florida State and USC had values of 1.47 and 2.04, respectively. So there is hope for teams scoring just above the median!