The one thing I would tell a young pitcher is never walk the leadoff man. He always scores; he always scores.David Smith, the man who started and runs Retrosheet, thought he would check that out (though, obviously, a leadoff batter who walks does not always score). Smith looked at 29 years (1974-2002) worth of data: 61,365 games, 1,101,019 half-innings, more than 4.5 million plate appearances.
Reached Scored FrequencyA leadoff batter who walks does not score at a significantly higher rate (statistically speaking) than a leadoff hitter who singles.
BB 82,637 33,002 39.9%
1B 183,468 72,841 39.7%
2B 48,364 30,961 64.0&
3B 6,573 5,753 87.5%
HR 27,205 27,205 100.0%
HBP 6,217 2,543 40.9%
E 12,105 5,298 43.8%
In August 2006, McCarver said:
There is nothing that opens up big innings any more than a leadoff walk. Leadoff home runs don't do it.* Leadoff singles, maybe. But a leadoff walk. It changes the mindset of a pitcher. Since he walked the first hitter, now all of a sudden he wants to find the fatter part of the plate with the succeeding hitters. And that could make for a big inning.* - Sorry, Tim.
Leadoff 0R 1R 2R 3R 4R 5R 6+RThe percentages for that chart:
1B 183,468 104,074 35,868 22,726 11,329 5,375 2,415 1,681
BB 82,637 46,794 15,837 10,481 5,167 2,503 1,100 755
Leadoff 0R 1R 2R 3R 4R 5R 6+RWhether a leadoff batter singles or walks has no correlation with how many runs his team will eventually score in that inning.
1B 183,468 56.7 19.6 12.4 6.1 2.9 1.3 0.9
BB 82,637 56.6 19.2 12.7 6.2 3.0 1.3 0.9
Smith, from The Baseball Research Journal 35 (2006):
[A]necdotal observations and gut feelings are just that and have no inherent credibility, no matter what the source. Since we can now check these opinions with evidence, and McCarver definitely has at his disposal the talents of people who can do such checking, then we should expect him and other announcers to get it right.It is not only McCarver. In May 2008, Blue Jays announcer Rance Mulliniks estimated that a leadoff walk comes around to score 60-65% of the time. But why estimate when the facts are available with a little bit of effort (even as little as asking an assistant to do some research)?
More recently, plen had a similar post at Fangraphs in September. Looking at the data from 1952-2009:
Leadoff Scored FrequencyAgain, leadoff singles and leadoff walks come around to score at the exact same rate, statistically speaking.
1B 325,455 122,662 37.69%
BB 150,570 57,189 37.98%
HBP 11,865 4,600 38.77%
E 19,260 7,270 37.74%
Richard Griffin of the Toronto Star has a lengthy Q&A with Blue Jays manager John Farrell.