Party Like It's 1999

During a recent trip through the pages of baseball-reference.com, I came across a very interesting anomaly.

It was a stark and obvious statistical aberration that I had never noticed before, and it led me to similar discrepancies that in turn led to some questions. Before I pose them, let me present the information.

Cal Ripken, Jr. is a career .276 hitter. During the 1990s, he progressed through his 30s with numbers that were fairly consistent with his overall totals:

Year Age PA AVG OPS
1990 29 695 .250 .756
1991 30 717 .323 .940
1992 31 715 .251 .689
1993 32 718 .257 .748
1994** 33 484 .315 .823
1995 34 613 .262 .745
1996 35 707 .278 .807
1997 36 686 .270 .703
1998 37 659 .271 .721
1999 38 354 .340 .952
2000 39 339 .256 .763
2001 40 516 .239 .637

*OPS= On base % + Slugging %
**strike-shortened season

In looking at these numbers, there is one exception that stands out. In 1999, at the advanced age of 38, Cal Ripken Jr. posted career highs in batting average and OPS.

His average took a 70 point leap from the previous season, and his OPS skyrocketed by more than 200 points. At an age where most players are retired or serving as reserves, Ripken had the best offensive output of his entire career. A .340 average!

Now the first thing that should come to mind is,

"Yeah, but he only had about half of the typical number of plate appearances."

That's correct- 1999 was the first season in which Ripken sustained serious injuries. It marked the end of "the streak" as he sat out most of April, half of May, and all of August. And it could be that the diminished sample size (i.e. fewer plate appearances) accounts for why he was able to sustain such a high output.

However, a discrepancy of this size is pretty unusual, even for a guy like Ripken who had previously enjoyed a handful of "boom seasons" where his totals spiked to exceed his typical performance (e.g. 1991).

Moreover, the man was 38 years old with an unprecedented amount of mileage on him. It was by any measure an odd time to have the best performance of one's life.

And there's more. Looking at Ripken's splits for 1999, an interesting pattern emerges.

April: .179 avg/ .457 OPS
May: .279 avg/ .897 OPS
June: .352 avg/ .945 OPS
July: .413 avg/ 1.179 OPS
Sept/ Oct: .365 avg/ .961 OPS

(To put this perspective, an OPS of greater than .900 is typically the realm of elite hitters like Albert Pujols.)

Ripken was hobbled in April and early May, during which he played a combined 24 games. Yet when he returned from injury he almost immediately began performing at a level that exceeded anything he had previosuly done at the plate.

Just as suddenly, he was injured again, missing all of August. And yet his second return, in September, was just as successful.
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What's my point?

In looking at these numbers, I found myself asking this question:

How does a 38 year old man with a lot of wear and tear suddenly bust out his best offensive showing ever, despite being seriously injured for the first time in his career?

Thinking about that question led me to this one:

Is it meaningful that this happened in 1999, the year after McGwire and Sosa combined for 113 home runs?

I know, I know...to even consider that a baseball Golden Boy like the Ironman did something to aid his performance or recovery is tantamount to blasphemy...but nevertheless, the increase in production is pretty damn large to be accounted for by a "hot streak" or some other natural variance.

In an attempt to explain it, I began looking at other players. In the same year, Rickey Henderson, another future Hall of Fame superstar, turned 40. Despite reaching that milestone, Henderson enjoyed an amazing offensive resurgence of his own as evidenced by the numbers below:

Year Age OPS
1996 37 .754
1997 38 .742
1998 39 .723
1999 40 .889
2000 41 .673
2001 42 .717
2002 43 .721
2003 44 .627

With the exception of the final two years, Henderson had 400+ plate appearances in each season, providing large enough sample sizes for comparison purposes. Note that his OPS in 1999 was his highest since the end of his "prime" (age 34) in 1993.

Rickey's OPS jumped more than 160 points from 1998 to 1999, yet immediately dropped back down the following year.

Again, I was forced to ask myself a question:

How does a 40 man suddenly elevate his offensive production to a level not seen since his prime?

My first thought was that perhaps offense in general was up that year. Many of you may recall discussions about the baseball being "juiced". Could there have been an overall increase in offensive production?

In the National League (where Rickey was playing), both runs and home runs did increase substantially from 1998 to 1999. However, those global totals stayed higher in 2000 and 2001 as well...Rickey's individual performace did not.

This seems to suggest that his offensive spike was not necessarily a result of league-wide production.

In the American League, there was no significant increase in offense at all. 1999 run and home run totals were consistent with the numbers throughout the 90s, as well as the totals posted in 2000 and 2001.

Again, this suggests that Ripken's numbers cannot be attributed to some larger phenomenon.

So if Ripken's and Henderson's aberrant performance cannot be accounted for by overall trends, and if they're too extreme to be reflective of random variations in performance, how can they be explained? Two players, both at ages that typically involve substantial declines, suddenly bust out. And there may be others beyond these two- I'm still checking through the numbers.

To be clear, I'm not accusing Ripken or Henderson of using PEDs. But the numbers are very interesting. Could it be a coincidence? Sure. But the timing, the patterns, the ages...it makes me wonder. We're in a time where every "power hitter" is under suspicion and scrutiny. Should we not examine other players as well? At the least, it's an interesting phenomenon worth a long look.