Friday, October 10, 2008

Bo Ryan and the Amazing No Foul Defense

On March 15, 2008, Wisconsin defeated Michigan State by two points in the Big Ten Tournament. This was not a shocking result - both of these teams were very good last season. But the way in which the game unfolded had Spartan fans howling. Wisconsin attempted 37 free throws to MSU's 19. Moreover, Wisconsin attempted 46 field goals to MSU's 50. For those of you scoring at home, that's a Free Throw Rate of 38.0 for MSU, and a rate of 80.4 (!) for Wisconsin. To say it was the difference in the game is an understatement.

But this is nothing new for Bo Ryan's teams at Wisconsin. Ever since Ryan took over in 2001-02, the Badgers have enjoyed a considerable "fouls per game" edge against their conference opponents:

In the last two seasons, this edge has risen from 2-4 fouls per game to 5 fouls per game. And it's not as if the Badgers are drawing fouls at a higher rate - this has stayed relatively constant under Ryan's tenure. No, it's just that the defense has stopped fouling.

One thing that appears relatively clear, however, is that this is not the Kohl Center at work. Ryan's teams draw fouls at a very steady pace throughout the season:

Wisconsin Conference Fouls per Game, 2007-08 season:

But is this a skill Ryan has taught his players, or is it superior advocacy that he brings to the sidelines? To investigate, I've looked at various defensive metrics, to see if the Badgers are making a trade-off here.

Conference Opp. FG Percentage:

Conference Opp. 3P FG Percentage:

Conference Opp. Offensive Rebounding Percentage:

Wisconsin Conf. Block Percentage:

Wisconsin Conf. Steal Percentage:

Conference Opp. TO Percentage:

I have to come clean here. I wanted the numbers to show me something. Specifically, I wanted the numbers to show me some trade-off that Ryan's teams were making, as a cost of not fouling as much. I can believe that Ryan has figured out how to play solid defense without fouling, but it's hard for me to believe that doing so comes at no cost. Of course, that doesn't mean that can't happen. It's entirely possible that Ryan is a defensive genius who has figured out something that other coach has been able to copy...but that doesn't sound very likely. All innovative coaches adopt a strategy at some cost - whether it's the POT ("perimeter oriented team") that has trouble rebounding its misses, or the very tall team that loses guard skills. There's no such thing as a free lunch.

And as I was putting these graphs together, every single one was disappointing and offered no explanation for the foul gap...until I got to the Conference Opponent TO Percentage, the very last graph shown. Opponent TOs have dropped substantially in Ryan's tenure, and that offers up a plausible explanation behind the foul gap. From the looks of it, Ryan's teams do not pressure the opponent into mistakes. Less ball pressure equals less fouls.

Of course, this is far from proof, in either direction. The TO Rate could be a coincidence. No doubt some will note that the TO Rate has reached its highest levels in Ryan's tenure at the same time that the foul gap is the largest. Maybe there is no clean story here, and we go right back to Badger fans singing the praises of Ryan's genius, and the rest of the Big Ten crying foul. We don't really know for sure, but for my money, I'm sticking with the TO theory.


turomon said...

Your conclusion about trading steals for fouls is consistent with observation. Bo's teams play position defense, rarely if ever double team the post, and don't crash the boards on offense in the name of getting back on defense. He talks about "showing your hands" to the ref on defense, I believe, to avoid fouling. His teams get few breakaway baskets, and they give up few breakaway baskets (hence the fewer possessions per game).

Given the high PPP for possessions that end in freethrows, it appears to make sense.

Josh said...

Ryan definitely makes it work, but I won't weigh in on whether or not it's a superior strategy in general. After all, we're talking about a 2-5 foul gap here, and only a portion of those add to the FTA total. I'm not sure I can quantify how many TOs Ryan's teams give up as a result of this, but it might be an even trade-off, or even negative. I can't say at this point. But Ryan has definitely made it work with his teams, and it's hard to argue with his results.

As for OReb%, crashing the offensive glass definitely seems to be a Ryan staple:

Maybe it's just him playing better rebounders, but it's hard for me to believe at this point that Wisconsin is not upping their rebounding efforts under the Ryan regime.

phdballer said...

Interesting stuff. Love the blog.

A question I have: How do these yearly trends compare to the Big 10 overall? Have there been any shifts in the play of Wisky's opponents that may have contributed but wouldn't be apparent by just looking at Wisconsin's stats?

Aside from two years (0405 & 0506 - possible outliers?), the overall trend for Opponent TO appears to be a gradual decrease since 9697. I wonder if the overall Big 10 compares similarly during this time frame. Or, has the Big 10 been flat (or increasing) and Ryan's teams have fallen well below average?

kj (spartans weblog) said...

One wonders whether the nature of Wisconsin's offense helps them with fouls on both sides. Almost every Badger can post up. Therefore, they all have to guard players posting up more often in practice, so Wisconsin learns to play defense down low with good position.

On offense, teams aren't used to defending players who can post up in today's college game, so they create mistmatches that lead to getting fouled more often.

As a Spartan fan, of course, all of this drives me crazy.

Tom said...

There are a number of elements that go into Bo's philosophy of minimizing fouls, including position defense, moving your feet/not reaching (thus the lower number of steals and forced turnovers)and going straight up on shots - Badgers always have a lower block % and if you watch the majority of blocks come from weakside help not from the primary defender. The other thing to keep in mind is that Ryan stresses defense and if you can not play good defense you don't play. It takes a year or two for most players to understand and meet Bo's defensive requirements, which is why you rarely see freshman play for the Badgers.

If knowing how to teach basics and motivate players to buy into your philosophy is the criteria for being a defensive genius then Ryan qualifies - he would tell you that he is just a good teacher.

You might question the value of sacrificing forced turnovers to foul less, but since Ryan's Badgers are consistently one of the most efficient defensive teams in the country it would be foolish to question the value of his defensive philosophy.