Sac Flies: Smart Play?

Assume for a moment that players are trying to hit sac flies and they are not mere accidents or failures at the plate. John Walsh at The Hardball Times took a crack at this question in 2005, in this article. (Note, it does not address the question raised in my early post about why batters would be trying harder to hit sac flies with fewer strikes).

If the batters are trying to hit sac flies, is that smart?

We can use the average run expectation charts for 2007 to determine whether trying a sac fly makes sense.

Situation: 1 out, man on third. The RE for this is .975. If the sac fly succeeds, a run will score (1.0) and there will be two outs. Two outs and noone on base is .107. So if it succeeds, the RE is 1.107. If it fails, either because it doesn't result in a fly ball, or not a fly ball deep enough, there are two outs and a man on third, for an RE of .405.

The breakeven point is (.975-.405)/(1.107-.405) or 81.2%. The hitter has to succeed at least 81.2% of the time for this to be a smart play.

What if the hitter was trying to get a one base hit instead of trying for the sac fly? Assume failure is a strikeout and success is a single. That would be (.975-.405)/(1.528-.405) or 50.8%. Of course, no hitter can be expected to hit a single nearly 51% of the time.

Is it better to try for an 81% success rate on a sac fly, or a 51% success rate on a single? I don't know, but it seems like we'd judge in favor of a sac fly as the number of strikes on the hitter increases, since very few hitters are better with two strikes. Yet the data indicates far less success at sac flies as the strikes pile up.

The analysis is more complex when you factor in that walks, doubles, triples and homers are also safe possibilities for the hitter. Their break even points are: 69.9%, 43.2%, 36.3% and 30.4%. The probability of achieving those depends heavily on the hitter.

And of course, that's just one scenario. If it were men on second and third with no outs, the sac fly break even point would be (2.101-1.467)/(1.724-1.467) or essentially impossible to come out ahead.

Here are the breakeven points for sac flies in all the various base-out states (using 2007 RE):

Runners    Outs     Break Pt.
003          0        Never
003          1        81.2%
023          0        Never
023          1        Never
103          0        Never
103          1        98.9%
123          0        Never
123          1        Never

Even without factoring in the benefits of trying to get a base hit, the sac fly seems to be something you wouldn't attempt as a hitter except with a runner on third and one out. And then, you'd have to be 81% sure that you could do it, as opposed, to say, striking out.

By the way, Tim Kurkjian at ESPN was either bored, or he really likes the sac fly.