I just saw an article by Tom Haudricourt of the Milwaukee Journal Sentinel on how the new Brewers manager will be more aggressive on the bases… I find it interesting that new managers always say that (kinda like new basketball managers saying they’re going to focus on defense, Scott Skiles). Anyways, I always thought that getting thrown out on the bases was really bad because you not only lose the runner on base, but you add another out to the inning (totally against Moneyball). Since I’ve been reading a lot of Advanced NFL stats (I love constantly looking back at win probability chart of the Superbowl and seeing the “100% win probability for the Pack at the end of it), and since I’ve been trying to fill the football void, I decided to try to figure out being more aggressive was the right move or not for baseball.
First thing I did was find out the run expectancy (i.e. how many runs you’d expect to score in an inning with certain runners on base). I found one table here. Taking these numbers, I figured out the “breakeven” probability for taking an extra base. In other words, you’d hafta make it XXX% of the time for it to be worth it. I only did it for a single runner on base, I’ll try with more runners on base at a later date. But here’s the results:
For going from 1st to 2nd, you had to make it more than 73-75% of the time for it to be worth it. The number of outs didn’t really matter too much. This makes sense because 2nd base is scoring position, so it didn’t matter if you made the first, second, or third out there, getting to 2nd was the same.
For going from 2nd to 3rd:
0 outs: 75%
1 out: 70%
2 outs: 89%
The adage of not making the last out at 3rd shows up here. You better be 90% sure you’ll make it if you try for 3rd with 2 outs.
For 3rd to home:
0 outs: 94%
1 out: 73%
2 outs: 35%
If you think making the last out at 3rd is a sin, making the 1st out at home is a bigger sin. The more interesting thing here is you should go for home with 2 outs if there’s a better than 35% chance you’ll make it. That means you should be thrown out at home 2 out of 3 times with 2 out. How many 3rd base coaches would get fired if that happened? Granted, this is assuming no other runners on base. So this is for a sac fly with a man on 3rd with 1 out, or a wild pitch opportunity, or even stealing home. What’s the success rate of stealing home right now?
Even looking at the other numbers, it looks like it’s beneficial to run if you can make it more than 75% of the time. So 1 out of 4 times, you should get thrown out trying to get to 2nd. That definitely feels like a lot, and many players would get benched for that.
So overall, my tune has changed. Apparently going for extra bases is like going for it more often on 4th down. No one gets fired for punting. I guess no one gets fired for not taking extra bases!