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View Full Version : KenPom analyzes whether/when to foul if tied, up 1 or up 2



Nugget
07-22-2020, 01:11 PM
KenPom has a piece to fill the summer doldrums that moves past the familiar question whether to foul up 3 to the question whether to foul late if up 2, up 1 or tied. https://kenpom.com/blog/

The takeway - including a statistical note that I hadn't seen pointed out before, but jibes with my "eye test" instinct, that free-throwers tend to do worse on their first shot than their average:

We see that the strategy is most viable for teams up 2, especially for underdogs in the single-bonus. As shown with the USF/BYU case, underdogs up 2 are trading only a slight increase in the chance of overtime for a significantly increased chance of winning in regulation when they foul.

The strategy is also quite useful for underdogs when tied in the single-bonus due to the chance of a poor free-throw shooter missing the first attempt and giving the fouling team the final possession in a tied game. In a tie game, fouling increases one’s chance of winning if the game ends in regulation and reduces the chance of overtime. So there’s a strong underdog effect here since they suffer more than a favorite in an overtime situation relative to ending a game in regulation.

We should note that when implementing this strategy, it’s important to consider that a player’s season-to-date free-throw percentage may not accurately represent his true ability. In particular, players are worse on their first free-throw attempt than their season average. In games involving power conference teams since 2010, players have made 67.4% of their first attempts and 73.1% of their second attempts in two-shot foul situations. That’s important in the single-bonus situation where the chance of making no free throws is extremely beneficial to the fouling team.

At any rate, the math is clear. When tied or up 2 on defense and the shot clock is off, teams can benefit from putting a below-average free throw shooter on the line. Especially underdogs in the single-bonus.

throatybeard
07-22-2020, 01:24 PM
Did they factor in whether the foul shooter is Tre Jones?

DU82
07-22-2020, 03:17 PM
Did they factor in whether the foul shooter is Tre Jones?

He only misses second shots. Intentionally.

devildeac
07-22-2020, 03:35 PM
He only misses second shots. Intentionally.

Worthy of watching again. And again. And again...


https://www.youtube.com/watch?v=D7EjTsIMAx8

flyingdutchdevil
07-22-2020, 03:35 PM
At any rate, the math is clear. When tied or up 2 on defense and the shot clock is off, teams can benefit from putting a below-average free throw shooter on the line. Especially underdogs in the single-bonus.[/I]

Eek! Can you imagine the public reaction if you're tied, you foul the opponent, the opponent makes at least one FT, and then you lose the game on a last-second shot? The coach would get crucified. Even if the math supports it, a coach would never go down that route.

Up 2 makes sense to me and is a solid choice (if your name isn't Roy Williams, of course). But tied? Even if the math makes sense, that's insane.

OldPhiKap
07-22-2020, 03:40 PM
Up 2 makes sense to me and is a solid choice (if your name isn't Roy Williams, of course).

One of the beautiful parts of last season was that Roy lost doing it both ways. And got merciless grief from the IC bleacher bums both times.

Heh. Rot in Hell, cheaters.

UrinalCake
07-23-2020, 02:42 AM
The problem with this analysis is that KenPom is using historical data to determine the probabilities of certain events occurring. But that doesn’t factor in a.) the strengths/weaknesses of your team as well as your opponent’s, or b.) the fact that these decisions were not made randomly, but by coaches who took numerous factors into account, and those factors may not be relevant to your particular situation.

So it might be that the team at the line only gets an offensive rebound off a missed free throw 25% of the time when looking across all of college basketball. But if you’re facing UNC or a team that you know is a good rebounding team, that changes the equation. Also, it’s easy to say “just foul the worst free throw shooter on the other team” but obviously the other team knows that you want to do this and so will do everything they can to keep the ball out of his hands. Being at home versus on the road makes an enormous difference in whether you play for overtime, as does your team’s depth/fatigue, foul situation (both player and team counts), pace of play, and dozens of other factors.

FDD brings up a good point though, which is that the fear of looking foolish is a big motivating factor. Malcolm Gladwell did a study several years ago where he studied penalty kicks in soccer and boiled it all down to shooting left, right, or down the middle. What he found was that statistically the highest probability of scoring would occur from kicking it right down the middle, because the goalie always guesses to one side or the other. However, the embarrassment of kicking it right at the goalie and having it blocked would be so great that no player would ever do this.

chrishoke
07-23-2020, 11:39 AM
Valvano says hi.