What's so magic about 100 pitches?

When Ozzie Guillen showed the baseball world in the playoffs that it's OK to keep starting pitchers in for the whole game, I was rejoicing because he was providing some evidence for my theory that today's managers tend to baby their starters. I believe that pitchers get stronger by pitching longer into games.

In the new book from the guys at www.hardballtimes.com, The Hardball Times Baseball Annual 2006, I had an article titled the same as this Stat of the Week, "What's so magic about 100 pitches?" In summary, there is evidence that starting pitchers who average at least 100 pitches per start in the first half of the game tend to improve in the second half. This is especially true for the best pitchers. Here's a chart, arranged by first half ERA, that summarizes the results.

While there are other factors that may be coming into play (injuries, for example), this does provide some cause to consider having pitchers go deeper into games.

Click here for more information about The Hardball Times Baseball Annual 2006.