Originally Posted by

**leewileyfan**
One thing that had me scratching my head a bit was this: Piazza threw out 423 would-be base stealers but allowed 1,400 to succeed. Sabermetricians have devised formulas that indicate a success rate of 65% -73% [depending upon whom you are reading] necessary to make base stealing a worthwhile strategy. I GET that.

I also "get" that the core of the numbers stems from the 24 base-outs run expectancy grids that are updated quite often to capture current run scoring climates.

Here's the rub, for me. The 24 base-outs grid tells us [using a very basic example; runner on 1B and 0 outs] that we have a run expectancy of .413 [example only]. IF we had a runner on 2B with 0 outs, our run expectancy would be .482, an increase of .069, or an increase of 16.7% in the odds for us getting a run scored.

However, it is a gamble. I we try and our "stealer" gets nailed, we have nobody on base and 1 out. Now our odds of scoring are .298, a drop of 27.85% in our likelihood of getting a run home. Yes, I get the steep penalty paid for failure at a theft attempt.

Sabermetrics distills this to the following: a successful steal is +.18 and a nailed runner is -.47. Therefore, Piazza's 423 CS @ -.47 for his opponents [and to his credit], while his 1,400 runaways amount to only .18 apiece [1,400 * .18 = 252]. I see how, arithmetically, the whole base running drama costs Piazza only 60 or so defense runs or Catch -61. For me. this SEEMED counter-intuitive.

The original situation, 1B and 0 outs [.413] became, in actuality .481 [+ .068] 1,400 times in Piazza's career. The reduction of 423 rub-outs, which I can see at .298 [after the fact] - .413 = -.115 per event = 423 * .115 = 48.65 runs saved for Piazza

1,400 * .068 = 95.2 run expectancy improvements at Piazza's cost.

However, at a cost of -.115 per event, the 423 he nailed = 48.65 runs prevented to his credit. Now, having walked it through this way I can appreciate the shorthand of .18 and -.47.

While my metric has Piazza at -60 or so defense runs, I had thought his throw out rate was far more costly an element. The metric gets it right; but I learned something from this exercise. [Sometimes one has to take the long way home to appreciate the shortcut].

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