Back in the 1960's, when I started my baseball analysis work, there was virtually no source of play-by-play data of any kind. The data I used which ended up in The Hidden Game of Baseball in the 1980's was obtained from the play-by-play accounts of thirty-five World Series games from 1956 to 1960 in the annual Sporting News Baseball Guides. George Lindsey gathered play-by-play data from over 300 games in 1958 and 1959 and published several articles in the Journal of Operations Research in the early 1960's analyzing game strategy. Earnshaw Cook's work in the mid-1960's involved strategy and player evaluation and was based on simulations. Eldon and Harlan Mills commissioned the Elias Sports Bureau to produce computerized play-by-play data for 1969 and 1970 which was used for their Player Win Average calculations, a new player evaluation method. They did not tackle strategy. Unfortunately, they were ahead of their time, and their work did not catch on.

Now there are a great many play-by-play databases that are available to everyone. The whole process was kicked off by Bill James, because he had trouble getting data for his annual Baseball Abstracts in the late 1970's. Bill's multitude of readers were encouraged to team up to gather and share data by scoring games at the ballpark or from radio and TV game broadcasts. This developed into Project Scoresheet in 1984.

Gary Gillette has kept the effort going until this day, first with Project Scoresheet through 1990, then with his Baseball Workshop through 1996, and now with 24–7 Baseball. Meanwhile, Dave Smith (who had helped tremendously with the last few years of Project Scoresheet) got into the act with Retrosheet in 1989. Retrosheet started to collect pre-1984 games and now has posted almost every game back to 1960 on its website at www.retrosheet.org. Gary provided 1984–1990 games to Retrosheet from the Project's files after its demise, as well as making available raw game stats for 1991–1998, which were the basis for the Retrosheet game logs. Dave later obtained 1991–1992 play-by-plays from STATS Inc. Retrosheet recently has also been publishing current seasons, which are now available back to 2000.

So now between Dave and Gary and the hundreds of volunteers who have contributed to Project Scoresheet and Retrosheet, we have over 45 years of games available for analysis. Dave is busy collecting games back to 1900 (and earlier), and already has hundreds of games from almost every season in the past century.

This vast source of data has permitted very detailed analysis of strategy, which Tom, Mitchel, and Andy have used to its fullest. Their analysis of the sacrifice bunt, stolen base, intentional walk, and pitchout are more thorough then any I have seen. Construction of the lineup, including platooning, and the use of starting and relief pitchers provide some fascinating results as well. There are no simple answers to the questions of strategy, but the information presented herein would be helpful for anyone actually charged with making strategic decisions, as well as being interesting to the average fan who likes to delve into these matters.