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Baseball Judgments

Baseball Judgments | SportsLibrary.net

The confusion about stolen bases

 

By Roger Weber

 

Occasionally a team wins a game because of a stolen base. It's rare, but it happens. Stolen bases, though, are generally not held in high esteem in the statistical world of baseball. Players like Ichiro Suzuki and Scott Podsednik are generally not considered on the same par as players with similar on base percentages, more power but less stealing ability.

 

Stolen bases themselves are not bad. If there were no consequence for a failed steal attempt there would be no harm to them and their benefits would be notable. After all, stolen bases, when successfully completed, can turn singles into doubles, doubles into triples and increase a team's probability of scoring runs in an inning. When a steal attempt fails, though, and a player not only is knocked off the base path but also costs his team an out, the consequences are generally believed to far outweigh the benefits of a successful steal attempt.

 

Base stealers and players who at least threaten to steal do add an element of suspense to the game. They make pitchers uneasy, force them to throw from the stretch position and generally are quicker players in general. They usually have a good chance of taking an extra base on a hit. Stolen base totals correlate better with triples than with any other positive offensive statistic. This makes sense as smart managers will only have their smartest base-runners attempt to steal.

 

Unfortunately for the sake of this element of the game, an element that used to be a much more important part of the game, there is not a terribly large amount of evidence supporting the value of the stolen base. Since the inception of three divisions in 1995, teams leading their division in stolen bases finish lower in the standings than those leading in other stats like home runs, doubles and triples.

 

With simple statistics we cannot tell the value of stolen bases in the minds of players. There are ways we could measure the effects on pitchers of having a stolen base threat runner on base behind him, but they probably wouldn't be that accurate without going through box scores and tapes of thousands of games.

 

What I can do, though, is look at the actual value of stolen bases and caught stealing attempts as far as they equate in run production. Remember, this information discounts all the "intangible" effects of base stealers.

 

One of the more popular measures of the value of stolen bases is a stolen base runs, commonly abbreviated SBR. Although not developed this way, one explanation for its basic formula, (.3 x Stolen bases) – (.6 x caught stealing), is that for a player to score, he needs to advance four bases during the time of two outs, since the third out ends the inning. This makes outs twice as costly as additional bases are beneficial. Although some researchers dispute the stolen base runs idea, it does shed some light on why some players have less value than it appears. In 2003 Juan Pierre had 65 steals but was caught 28 times. According to this formula, his steal attempts only gained his team about three runs all year.

           

Here's another way of considering the value of steals. The goal of a hitter is to first drive in runs while he is at the plate and then to score while he is on base. While on base, he must travel a certain number of bases during the time a certain number of outs are collected. Assuming the weights of being on the different bases are linear, that they are equal in value, which they aren't, here's how stolen bases and caught steals affect a runner's progress. The table also assumes that these are the only six times stolen bases happen, which they aren't. The second, third and fourth columns represent the number of bases per out the runner must travel. Under "CS" this means that the runner is removed from the base path and the player at bat is the next scoring option.

 

Outs

Runner on

No attempt

SB

CS

Cost of CS / Benefit of SB

0

1st

1

2/3

2

3

0

2nd

2/3

1/3

2

4

1

1st

3/2

1

4

5

1

2nd

1

4

6

2

1st

3

2

-

-

2

2nd

2

1

-

-

 

This table isn't scientific but it does give us an idea of the value of a failed steal attempt. It can cost a team much more than a stolen base may gain it. This, again, isn't a universal rule but it is an average.

 

Here is a more scientific look at the respective values. In "The Book: Playing the Percentages in Baseball," there is a table of run expectancies during different situations from 1999-2002. Borrowing those data, I have put together a table similar to the one above, except that instead of measuring bases per out needed to attain a run, it lists the average number of runs a team will score in the inning from different base and out situations. In the table, where runners are listed at first and second, the stealer is assumed to be the player at second base and where players are listed at first and third the stealer is assumed to be the player on first. Steals of home are not measured because those attempts are rare.

 

Outs

Runner on

No attempt

SB

CS

Cost of CS / Benefit of SB

0

1

.953

1.189

.297

2.78

0

2

1.189

1.482

.297

3.04

0

1 and 2

1.573

1.904

.573

3.021

0

1 and 3

1.904

2.052

.983

6.223

1

1

.573

.725

.117

3

1

2

.725

.983

.117

2.357

1

1 and 2

.971

1.243

.251

2.647

1

1 and 3

1.243

1.467

.387

3.821

2

1

.251

.344

0

2.699

2

2

.344

.387

0

8

2

1 and 2

.466

.538

0

6.472

2

1 and 3

.538

.634

0

5.604

 

If a player on first base with no outs steals second base, the average number of runs his team will score in the inning is a little higher, by almost a quarter of a run. If he is caught, though, his team's average number of runs decreases by about .66. So if he steals three times and gets caught stealing once, this table says he is benefiting his team. If he gets caught twice and steals three times, he is hurting his team. 

 

This is somewhat hard to understand because it doesn't relate perfectly, and in that sense isn't totally correct. These are average figures based on where the runner is, not on actual real-time events. The fact that a player takes an extra base does not mean his team will score more runs. This table simply shows that from that extra base there is a higher probability his team will score because on average, more runs are scored when the player is at the next base. The average cost of a failed steal is three or four times the benefit of a successful steal. Of course, averages like this don't follow the way straight numbers would. If a player is caught stealing, his team still has a decent chance to score a run, but it is significantly lower than if the steal had been successful.

 

Speedy base-runners and base stealers give a team a significant edge, what some fans would say is adding excitement. Repeated studies have shown the break even point for steals is around 60 to 70 percent, most usually about at 67%. This means that a player needs to be successful on 60 to 70 percent of his steal attempts to bring positive production to his team. And if the player is thinking about stealing, he should only attempt it he thinks he has a 60 to 70 percent chance of being successful.

 

What this table can tell us, and what many statisticians have already picked up upon, is that stolen bases are slightly more valuable than we often believe. The SBR formula, instead of using the idea of a 67% break even point and then multiplying times 0.3, should multiply the total to a factor around 0.5 or a little above.

 

Baseball statistics practices have long been criticized for their failure to accurately measure the value of stolen bases. And while I like to look to a little more than stats, the number crunchers are getting more accurate in measuring almost everything. 

 

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