I just listened to Denard Span short circuit a potential rally by trying to steal second base with runners on the corners and one out. He was caught. I wondered if that was an especially stupid decision.

It turns out, it's not that risky. Or at least it's not if you accept that a baserunner usually needs to steal bases about 2/3 of the time to be effective.

Generally, one studies something like this using Palmer & Thorn's Run Expectancy Matrix. It's a neat grid that shows, given a certain number of outs and people on base, the average number of runs that should score that inning, based on 75 years of major league games. It was published in The Hidden Game of Baseball by Pete Palmer and John Thorn. You can find it here.

Here's the numbers we care about:

1. 1.088 - That's how many runs a team on average would score with runners on 1st and 3rd and one out.

2. 1.371 - If Span would've stolen the base, that's how many runs the average team would've scored.

3. 0.382 - If he was caught, that's how many runs the average team would score.

So Span risked a gain of .283 runs if he stole that base, but a loss of .706 if he was caught. Converting those to percentages, if he steals that base 71% of the time, the team breaks even. That's not especially different than the 2/3 view that is the case for most base stealers. This wasn't especially risky.

I actually think it was a hit and run, and even if it wasn't, I disagree with the logic here. It evened up the count on Dozier, when it would have been 2-0 to a pitcher throwing poorly (horrible pitch). I also don't think you're looking at it quite the right way.

Base stealing typically considered risky for little gain in general with a drastic cost if caught. This was even more risky. Look at the numbers. If he is safe, he doesn't gain much. However, being caught means he essentially loses the chance for a run. A basestealer needing to be successful 71% of the time for the steal to be worthwhile is a poor play.

yes, it clearly was a hit-and-run. I get the above numbers, but when the team is struggling to score runs, I'm just fine with taking some chances with a hit and run there.

Span's been on base constantly this season and only has a handful of SB attempts. They need to be more aggressive in general, but especially when the speed guys are on.

Good analysis. Great book.

Always wondered if the run scoring context alters the table. The context would not only include era and park but also pitcher and ability of on deck batter and successive batters

I suspect that the payoff of stealing the base increases as the run scoring context decreases.

I agree.

This Team has to start taking some chances to get runners in.

I also believe that being a little more aggressive could help some of these guys a little. Put a spark back in there.