Following up on my previous article on Bert Blyleven, I thought I’d share some numbers I crunched regarding Blyleven being homer prone, as he supposedly was. I always suspected that Blyleven was prone to giving up home runs because as a curveball pitcher, he was liable to hang one from time to time and present the hitter with a juicy target. The homer-proneness of some curveball-reliant pitchers I’ve seen a lot of recently, like Scott Downs and Dave Bush, led me to surmise that curveball-first pitchers were just more prone to the home run than other pitchers, and that they would just have to make up ground with their fastball-throwing colleagues in other ways.
As it turns out, my supposition was wrong. I did a study involving a group of pitchers who primarily relied on their curveball, using the fine Neyer/James Guide To Pitchers as my bible and selecting only players who:
1. primarily played after 1946, to give a relatively consistent environment for home runs;
2. had a curveball listed by Neyer/James as their #1 pitch, at least throughout most of their career.
I tried not to inject any of my own biases by making separate determinations of whether a guy was really a curveballer or not. I picked 30 such pitchers (everyone in alphabetical order up to Wayne Garland) and looked at their innings pitched, ERAs, walks and home runs allowed, all in absolute terms and relative to their league.
Going the players and assigning numbers, I already knew that my supposition wasn’t going to prove correct. Yes, there were quite a few curveballers (even some good ones) who were really gopher-prone and managed to be successful in other ways. Call these guys the “John Cerutti types.” But there was an equal number of guys who used Uncle Charlie in an entirely different way … much wilder than the first group and very hard to hit for power. Call these guys the “Mark Clear types.”
Anyway, the upshot of it all was that the Mark Clear types and the John Cerutti types were a wash. The curveballers as a whole didn’t look to be giving up that many home runs, probably no more than average. (Taking into account that these were a good group of pitchers, due to the selection bias of getting into the Neyer/James book, they probably gave up 5% more than average.)
I intended to compare these 30 guys to a group of pitchers who had similar numbers and effectiveness but who were fastball pitchers. Then a funny thing happened which gets to the real point of what I’m writing about.
Thinking that I would compare the group of curveballers to Blyleven himself, I threw in his numbers at the end of the spreadsheet. And what did I see, immediately, that made me instantly realize I could have saved myself a hell of a lot of time?
Bert Blyleven gave up 14 fewer homers, over his career, than an average pitcher in his leagues.
Well smack my ass and call me Susie. Ol’ gopher ball Bert was above average at preventing the home run? Why did no one tell me this?
What bothers me is, ever since this research project was stimulated by an offhand remark of Mike D of Batter’s Box, that Bert had a “gopher ball problem,” and I had never bothered to question the underlying assumption. Thinking back over how I could have missed this relatively obvious fact, three things stood out as possible explanations (other than my own cluelessness, which obviously played a considerable role):
1. Blyleven does own the major league record for home runs allowed in a season, with 50 in 1986.
2. My own “mental picture” of Bert Blyleven was formed around this time, when he had moved from the indifferent Indians to the improving Twins. In fact, when Blyleven really captured my attention it was 1987, the Twins were pushing towards an eventual World Championship, and Blyleven had just come off setting that home runs allowed record. The gopher ball was constantly discussed as his Achilles heel. The impression couldn’t help but color my impression of the man.
3. I had become seduced, as I had been for some time, by the “hanging curveball” thesis, again letting it color my impression of Blyleven.
Finally, I think there’s a general impression that Blyleven was homer-prone. There must have been; that’s why Denyszyn would have brought it up, and why no one questioned him when the remark was made, and why I’ve heard similar sentiments being expressed elsewhere.
Recently, I wrote a short post over at my blog that talked a little bit, in a preliminary way, about how we tend to build our knowledge about baseball and ballplayers. One of the most deep-seated biases that we face when we are thinking about players is how statistics can create a powerfully misleading impression of who a player is, and Gopher Ball Bert is a perfect example of this. Bert spent two seasons giving up lots of home runs, and because that fact sticks out in our memory, we use it as a label for the man, instead of looking at his long career in which he resembled a Tommy John type more than a John Cerutti type.
If a guy has played three full years and hit .288, .328, and .304, some people will inevitably describe him as a “.330 hitter.” If a guy has won 20 games twice in 15 seasons, every third mention of his name will employ a description of him as a consistent 20-game winner. We tend to use otherwise-memorable numbers as the standard not by which we measure players, but by which we label them and categorize them. When I was in my early teens, people constantly talked about Nolan Ryan as a guy who would go out and win 20 games a year; at that time he hadn’t won 20 in over a decade and had consistently won 11 or 12 games a year.
I had a similar discussion with a friend recently about Owen “Chief” Wilson; looking at a picture that I thought was of Wilson, he remarked that it couldn’t be; this player didn’t look fast, and Wilson holds the single-season triples record. Now it’s not fair to judge someone based on their naive impression of a ballplayer who last played 90 seasons ago and has been dead for over 50 years. But if I could find a more perfect example of a judgment based entirely on statistics that’s both wrong and a misjudgement, that would be it. In fact, Wilson wasn’t an outstanding triples hitter. Good, yes. But Wilson, despite the 36 triples, had a reputation as a slow-footed slugger; triples in the deadball era were a power stat, usually generated by walloping the ball over the heads of outfielders who played close in, and were doubly so in the cavernous ballparks that Wilson played in.
It’s easy to let a few “benchmark” numbers mislead us about a player’s true skills or performance.
Anyway, back to Blyleven. Thinking that maybe his homer-proneness would show up more if I compared him to his peers, the superior pitchers, I decided to look at guys who were Bert’s equals as performers. I compiled a list of pitchers (from 1946 to 2003 only) who pitched over 2,000 innings and had an ERA+ of 110 to 120 (Blyleven’s was 115 according to the Sabermetric Encyclopedia) and looked at their home runs allowed rates.
Blyleven ranked 23rd of the 35 pitchers in home runs allowed. Not great, for sure, but not at all bad either. Some of these guys predicated much of their repertoire on preventing home runs; both Dean Chance and Tommy John, for example, owe almost their entire career performance to above average home run prevention. If Chance had had an ordinary number of home runs allowed, he’d have been about 17 runs above average instead of 129. If Tommy John had had an ordinary number of home runs allowed, he’d have been about eight runs below average instead of 173 above.
The whole collection of 35 pitchers averaged 10% above average at home run prevention, while Bert was 3% better. So compared with his fellow top-quality pitchers, he was in the general range in terms of home runs allowed but not particularly homer-prone. The pitcher on the list who was most homer prone was John Candelaria, Blyleven’s teammate in Pittsburgh for three seasons.
So in the end, I think it would be unfair to say that Blyleven had a “gopher ball problem.” Call it something that, as Studes would say, I didn’t know last week.
Players between 1946 and 2003 with an ERA+ between 110 and 120 and more than 2000 IP, ranked by home run rate vs. the league average.
RATE HRA LEAGUE IP ERA+ 1 Dean Chance 165 122 202 2148 119 2 Al Leiter 143 169 242 2075 119 3 Tommy John 143 302 431 4710.1 112 4 Steve Rogers 143 151 215 2837.2 115 5 Nolan Ryan 138 321 444 5386 116 6 Sam McDowell 138 164 226 2492 110 7 Mel Stottlemyre 137 171 234 2662 116 8 Tom Glavine 136 268 364 3528 119 9 Orel Hershiser 129 235 303 3130.1 115 10 Joe Horlen 127 145 184 2003 111 11 Dave Stieb 127 225 285 2895.1 118 12 Dwight Gooden 125 210 264 2800.2 113 13 Jon Matlack 121 161 195 2363 118 14 Chuck Finley 118 304 359 3197.1 115 15 Ken Forsch 114 155 176 2127.1 111 16 Tom Candiotti 112 250 279 2725 111 17 Gaylord Perry 111 399 443 5350.1 117 18 Jerry Koosman 109 290 315 3839.1 110 19 Frank Lary 106 197 209 2161.2 111 20 Mike Cuellar 106 222 236 2807 113 21 Vida Blue 104 263 274 3343.1 113 22 Early Wynn 104 313 324 3851 112 23 Bert Blyleven 103 430 444 4970 115 24 Steve Carlton 101 414 416 5217.1 113 25 Bob Feller 101 164 165 2307 119 26 Bob Welch 100 267 266 3092 111 27 David Wells 99 330 328 2826.2 111 28 Virgil Trucks 99 174 172 2306 113 29 Don Sutton 95 472 446 5282.1 114 30 Johnny Sain 93 172 160 2028 113 31 Jim Bunning 93 372 346 3759.1 113 32 Robin Roberts 93 505 470 4689 115 33 Dennis Eckersley 87 347 302 3285.2 113 34 Don Newcombe 87 252 218 2154.2 111 35 John Candelaria 85 245 209 2525.2 113