The payoff percentage of stolen bases (maybe Bill James knows)

[BiZmaRK]

What percentage does a player have to steal bases at in order for the gain of one base to offset the potential of losing a runner and having one additional out?

[Tango Tiger]

Roughly speaking, a bit under 70%.

It can be as low as 50% or as high as 90%, depending on the game situation. That's for stealing second.

For stealing third, the breakeven is much higher. For stealing home (with 2 outs), the breakeven is much lower.