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— Where BTF's Members Investigate the Grand Old Game
Monday, March 31, 2003
Beware of Falling Prices Strikeout Rates
Is Bartolo Colon’s declining strikeout rate a bad omen?
Last year, Bartolo Colon became the pitcher that his fans thought he should be. He won 20 games, posted an ERA below three, and would have been prominent in the Cy Young voting had he not spent half the season in each league. Of course, with the circus in Montreal, Colon immediately became the center of trade talks this winter, and was eventually dealt to the White Sox. Through it all, one thing disturbed me (and some others) about Colon?s wonderful season ? an alarming drop in his strikeout rate.
From the beginning of his career, Colon has been a power pitcher. In his first two years as a regular starter (1998 and 1999), Colon averaged seven strikeouts per nine innings ? above average, but not an exceptional rate in modern baseball. His walk rate in those years was also a little better than average, at 3.4 per 9 IP.
In 2000, Bartolo became a strikeout machine. In 188 innings, he struck out 212 batters ?10.15 per nine innings. His walk rate also shot up, all the way to 4.7 per nine innings. In 2001, both of those numbers fell back down to earth. Colon recorded his second 200-strikeout season that year, but his K rate fell to a still-impressive 8.14 per nine. His walk rate went to 3.64, which was a little worse than average. Bartolo was still clearly a strikeout pitcher, and still seemed on the verge of that breakout season.
Enter 2002. Before the trade from Cleveland to Montreal, Colon went 10-4 with a 2.55 ERA and an impressive walk rate of 2.4 per nine innings ? but only 5.8 strikeouts per nine. After going to the Expos, the walk rate and ERA increased some, but remained good ? but his strikeout rate went down even more, to 5.69. Overall in 2002, he struck out 149 batters in 233 innings, or 5.75 per nine innings. This was well below the MLB average of about 6.5.
Bartolo?s K rate was essentially the same in both halves of the year, and it doesn?t appear that he had some kind of injury that resulted in the strikeout drop. It seems that Colon just decided to stop trying to blow the ball past opposing batters and let his fielders do some of the work. As a result, his walk rate fell, and his baserunners per 9 innings was a career-best. The tactic worked; at age 29, Colon was one of the best pitchers in baseball last year.
Colon?s drop in strikeout rate was dramatic. Did I say dramatic? Actually, it was historic. The chart below is a list of pitchers since 1950 who, from the ages of 28 to 29, experienced a drop in strikeout rate of at least 1.50 strikeouts per 9 innings pitched (minmum 100 IP each year). Colon in 2002 had the fourth-largest decrease in strikeout rate for a 29-year-old pitcher.
The column “K rate change” in the above table means “change in strikeout rate from year 1 to year 2.” To measure value, I used two metrics ? Lee Sinins? Runs Saved Above Average and Bill James? Win Shares. Colon?s value skyrocketed in 2002, but eleven of the 16 pitchers above saw their value decrease, by one of the two value measures, in the second year of the study. This leaves five pitchers who, like Colon, experienced a significant increase in value along with a large decrease in strikeout rate:
Each of these guys improved from age 28 to age 29, despite experiencing a large dropoff in strikeout rate. Let?s take a look at each, starting from the bottom:
Steve Trachsel can hardly be compared to Bartolo Colon; Trachsel has never been a strikeout pitcher and his “improvement” was from 8-18, 5.57 to 8-15, 4.80.
Tom Glavine?s strikeout rate in 1994 is an aberration when compared to the rest of his career, and the decline from 7.62 to 5.75 K?s per nine innings is more of a return to normalcy than a dramatic change. His change in value in both Win Shares and RSAA, however, is identical to Colon?s, and Glavine also experienced a significant decrease in his walk rate. Of course, Glavine has remained a very good pitcher since then.
Bob Turley?s ages 26-27 seasons would look better in this study. Like Colon, Turley was a young fireballer who came into his own with a 20-win campaign (in Turley?s case, it was 21 wins) that was accompanied by a large drop in strikeout rate. In 1959, the 28-year-old Turley struggled, but he improved to respectability in 1960. It would be Turley?s last decent year, and he was finished by age 32.
Hard-throwing Jim Maloney had four straight 200-strikeout seasons in the mid-60s, and had a massive dropoff in strikeout rate from ages 28-29. One contributing factor to this decrease was surely the lowering of the pitcher?s mound in 1969. Despite all this, Maloney?s ERA improved from 3.61 in 1968 to 2.77 in 1969. Relative to the league, Maloney?s ERA was 17% worse than the league average in ?68, but 30% better than average in ?69. Maloney severed his Achilles tendon early in the 1970 season, and would not earn a single Win Share for the rest of his career.
The pitcher who may be the best match isn?t even in the study ? Andy Benes. Benes doesn?t make the study because his Year 1 came at age 27 (he?d make the 27-28 list, but this is a 28-29 list). Still, he matches pretty well with Colon. Both were power pitchers. Benes led the league in strikeouts at in 1994, at a rate of almost 10 per 9 IP, and his ERA was 3.86. Colon in 2000 had a strikeout rate of just over 10, and posted a 3.88 ERA. Both players had good strikeout rates the next season (Benes was at 8.47), and both saw their ERAs climb to above four. The next season, Benes? strikeout rate fell to 6.25, a drop of 2.22 strikeouts per 9 innings. Colon?s drop was to 5.75. Both pitchers also had improved control, and Colon had 20 wins and Benes a career-high 18. Benes? strikeout rate was back near 9 in 1997, but it fell off for good after that. He never again won more than 14 games, and only once reached 200 innings pitched. Benes was 34 last year, and appears finished.
I guess the key question I?m trying to raise is this: A pitcher with a low strikeout rate has a much shorter career expectation than a pitcher with a high strikeout rate ? but a good pitcher also has a much longer career expectation than a mediocre pitcher. In the case of Bartolo Colon, a rare trick has been turned ? simultaneously, a big decrease in strikeout rate and a big increase in value. How do you balance these two factors? Is he better off, in the long run, or worse? How much of one offsets the other? Is there a legitimate tradeoff?
I don’t know how to answer those questions, and I doubt anybody does. And so, like a basketball player unable to grab the rebound himself, I am flipping it up in the air, with the hope that maybe a teammate can pull it in. How can you even find a record of pitchers who have had simultaneous increases in effectiveness and decreases in K rates? How can you shake the data to make those guys fall out? And when you get the data, what do you do with it?
Colon will be a free agent after the 2003 season. If I?m a GM, do I want him on my team? Of course; the guy is a 20-game winner. But how much should I worry about that sudden drop in strikeout rate? And how the heck do you quantify worry?
Matthew Namee is a research assistant to baseball author Bill James and writes a regular column for StealHome.com, which launches on Monday, March 31
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