What Strategies Are Risky?

25 March, 1996

In an earlier article printed in JoBS, Basketball's Bell Curve, I described how using a risky strategy can help an underdog improve their chances and hurt a favorite. Something I didn't specify was what exactly is a risky strategy. This was pointed out by a reader whose email address did not work in my attempt to reply. To that reader: I hope you read this and thanks for the question.

Since "risky" is a fairly intuitive concept, I will name a few risky strategies before defining precisely what it means. First and most obviously, a press is a risky strategy because it often gets points off the defense or gives up easy baskets. A second risky strategy is to shoot a lot of threes; one is more likely to get 6 points or 50 points by shooting twenty three pointers Risky Press than by shooting twenty two pointers. A third risky strategy, though not as risky as the others, is to slow the game down, reducing the number of possessions in a game. These are the three fundamental risky strategies I have thought of. I will talk about others below.

Secondary risky strategies can be determined by looking at any strategy that leads to one of the above strategies. For instance, a zone often causes an opponent to take more three point attempts and to slow down the game, making it a "risky" strategy. I honestly never would have thought that a zone was risky, but the derivation is undeniable and experience mostly supports the notion (like the Syracuse win over favored Kansas in the West Regional Final). This is not to say that a zone should not be used by a favored team. If the favorite is a small team that has to stop an underdog with a good big man or no outside shooters, then a zone makes sense just because it affects the expected point differential. Safe Zone?

A second strategy that may be viewed as risky because of what it causes the opponent to do is play a lot of big men or players who do not handle the ball well. Doing this can incite an opponent into a press or pressure defense.

Calling these strategies "risky" is something of a misnomer. They are "risky" for a good team, but "calculated gambles" for poor teams. What these strategies do is make a team, whether good or bad, more inconsistent. Mathematically, they increase the standard deviation of their difference:

SD(Rating Difference) = SD(Rtg - Opp.Rtg)
		      = SQRT[Var(Rtg)+Var(Opp.Rtg)-2*Cov(Rtg,Opp.Rtg)]

Rtg:		Points scored per 100 possessions (offensive rating)
Opp.Rtg:	Points allowed per 100 possessions (defensive rating)
SD():		Statistical standard deviation of quantity in parentheses ()
Var():		Statistical variance of quantity in parentheses ()
Cov():		Statistical covariance of quantities in parentheses ()
All of the above strategies increase this term in one way or another. The press does it by making the covariance term smaller, even negative as it was for Georgetown in '96. Shooting threes does it by increasing the variance of the offensive rating term. Slowing the game does it by increasing both of the variance terms.

There are some other more subtle strategies that come out of this. For example, whether you front or back a post player can be regarded as risky or more conservative, respectively, because fronting is more likely to lead to a steal or an easy shot, while backing usually leads to a tough shot. (This is not always the case and depends on how the rest of the defense is taught to play, but is generally true.) If your guards go to the offensive boards (or follow their shot) rather than getting back, it can be viewed as relatively risky. As a result of this, if your defensive guards release rather than block out, that might be viewed as risky. If you overplay on the wings, it is riskier than playing position defense. And so on...

I am sure there are other subtleties of basketball influenced by this principle of risk, perhaps even some important ones that I have forgotten. However, this should be a good start. To emphasize, this principle affects the game by making teams more inconsistent. Perhaps a team plays a zone substantially better than they play a man-to-man defense; in this case, playing a zone makes sense regardless of whether that team is a generally good one or a generally bad one. Usually, it is difficult to explicitly evaluate whether a team is better at one type of strategy over another. This principle gives a good guide for when to use them, if there is uncertainty over which is best.

Again, my thanks to the reader who suggested outlining risky strategies.