What made John Olerud so much better after leaving Toronto?

23 years ago, the Blue Jays shipped John Olerud to the New York Mets, along with $5-million to cover most of his 1997 salary in exchange for Robert Person. It was a sad end to his time with the Blue Jays and ended up, like so much of Gord Ash’s tenure, not so great.

When Tom did his annual post on the trade last year (there’s not much else to write about the week before Christmas), I spent a little bit of time looking deeper into Olerud. I became a baseball fan in 1997, so what I remember of Olerud is entirely after his time in Toronto, and I was always bewildered the Jays let such a good hitter go. Something jumped out to me that I thought was interesting enough to write up, but time got away from me so I figured I’d save it for the anniversary this year and have a bit different look.

Famously, Olerud never played in the minors, coming directly to the Jays in 1989 and remaining with them through 1996. In essentially seven full seasons, he posted 3,681 plate appearances, posting a .293/.395/.471 line for a 130 wRC+ and 23 fWAR. Outside of 1993, he was never a truly full time player, but still averaged 527 PA and 3.3 fWAR per season — a very good player.

Those totals and that average is bolstered by that magnificent 1993 season, but the 179 wRC+ and 8 WAR are a pretty clear outlier compared to the other seasons. That’s not to dismiss it entirely, but merely to recognize how far it was from the rest of his season. We don’t want to cherry take, but if we instead take a trimmed mean and toss 1993 as well as his weakest season in 1990, Olerud totalled 2,581 PA, 13.5 WAR and a 118 WRC+. And the remaining five seasons were very consistent, with each within 10 points of wRC+ and 0.5 WAR of the average.

Which puts what Olerud did after leaving Toronto in even starker relief. In 1997, Olerud posted a 138 wRC+, and over the next six years posted 4,048 PA and 34 WAR, averaging 138 wRC+ and 5.6 WAR per year in 675 PA. He went from a solid regular to one of the best hitters and players in baseball.

So I was curious about what changed after Olerud left Toronto to make him so much better. What actually was surprising was how little did change:

Olerud did walk a little bit more, which isn’t that surprising given a higher level of production. But he already had a really good eye and plate metrics in Toronto, so this is really at the margins. Likewise, his elite strikeout rate was almost the same. He did hit for a little more power, with his ISO rising 12 points, but this basically just matched the increasing power league-wide at the time.

In fact, almost all the difference comes down to an increased rate of hits on balls in play. Olerud’s BABIP increased from a solid .292 in the trimmed 1991-96 mean (excluding ‘93), to a robust .318 from 1997-2002. BABIP is notoriously noisy, but these are both samples of 2,000+ balls in play. That 26-point difference in BABIP was worth 77 extra hits for Olerud in the six years after leaving Toronto.

I was very curious about what drove this. Unfortunately, we don’t the type of batted information or Statcast that is available today or for most of the 21st century. However, from about 1988 onwards, there is comprehensive play-by-play data from Retrosheet, available on Baseball-Reference (in the advanced batting stats tab). A little manipulation is required to get the conventional GB, FB%, etc, but one thing really stuck out:

I’ve simplified the table below to only focus on the years around the trade, but the years before and after are consistent. Look at that last column: Olerud’s pop-up (IF/FB) rate absolutely fell off a table. It must be noted that the Baseball-Reference data has a broader definition of popups than what’s at Fangraphs, probably something more like within 150 feet of home than about 110 feet, but I find the Baseball-Reference cutoff more useful.

As a Blue Jay, Olerud’s average of 13.7% of all balls in the air popped up was right around the league average of 14%. Though his popups had ticked up above league average his last three years at 16%, 15% and 20%.

His first year in New York, it ticked down to 13%, back in line with league average, and then fell dramatically the next year to an elite 5% level. It stayed there for the rest of his career. In those six years after leaving Toronto, he only popped up 6.9% of balls in the air. Excluding that transitional year of 1997, it was under 6% the rest of his career.

To put that in actual numbers, that means that with the Jays Olerud popped up about 216 times, whereas the next six years he only popped up 120 times despite 10% more opportunities. That’s about 100 less automatic outs.

The difference that helped his productivity was a small increase in line drive rate. Olerud was always a line drive hitter, with a 24% line drive rate in Toronto compared to 21% league average. In those big six years afterwards, it ticked up to 26.5%. Essentially, the evidence is that after leaving the Blue Jays, Olerud went from being very good at squaring up the ball to among the best in baseball.

Given the starkness and magnitude of the change in the popup data, I wondered it maybe there was something funny with the data. Perhaps popups were counted differently? But I spot checked numerous players whose careers straddled the 1990s and early 2000s, and none had a similar change. It appears it’s not an anomaly in the data.

So did the Blue Jays detrimentally affect Olerud’s career? Famously, Cito Gaston preferred that a first baseman be a classic “run producer” hitting for power and piling up RBIs, which wasn’t Olerud’s game. He thought Olerud should pull the ball more to tap into power, and in 1996 they brought in Willie Upshaw to work with Olerud on exactly this (notably, the season when his popup rate was highest).

As referenced above, Olerud wasn’t an everyday player under Gaston, platooning for the most part. It’s plausible to infer being freed from Gaston’s influence and able to play to his own game of spraying the ball to all fields is what allowed Olerud to flourish. The Globe and Mail on May 22, 1997 quoted Peter Gammons that the Mets had spotted a flaw in his swing and quoting a Mets coach: “we went back over the tapes for the last few years and his problems came from [] the use of his lower body”. There was also reference to him adding some weight and strength after leaving Toronto.

It’s of course unfortunate for fans that Olerud never replicated that 1993 form until he left Toronto. But there’s also a what-if regarding the Hall of Fame for him as well. His career was effectively done at 35, and with the style of his game he didn’t have a lot of the big offensive counting stats voters look for. But with 57 WAR, he’s approaching the borderline. With a few more allstar type seasons, maybe he’s in the 65-to-70 WAR range that would have him in pretty good shape.