How the game has changed in 25 years

[DrungoHazewood]

I was looking at the Red Sox and their pitcher's strikeout rate, which struck me (pun intended) as super-high. That led me to look at the rest of the league (they're actually behind the Tigers), and then to bb-ref's MLB totals page, which had a convienent divider between 1988 and 1989.

Here's how the game has changed since 1989:

Pitcher age: No real difference. It's been between 28.3 and 29.2 years the whole time.

R/G: Up 3% from '89, but that's tiny. Peaked at 5.1 in 2000.

ERA: Up 6%, mainly because...

Errors are down by 30%, from 0.8 per game to 0.55 so far in '13.

HRs are up 40%, despite the recent decline from the early 2000s peak.

Walks are almost constant, and that's despite a nearly 40% reduction in intentional walks from 25 years ago.

Strikeouts, which started this idea, are up 37%. An average game in 1989 saw 5.6 Ks, this year so far we're at a record high 7.7. That means two fewer real defensive putouts every game.

HBP are up a whopping 75%, but almost all of that came in the early 90s when there was a huge spike. We're acutally down from the peak of 0.39 per game in 2000.

Starters completed about 11% of starts in '89, now we're around 2%. Shutouts are down by about a quarter.

Saves have held nearly constant.

Hits per game are almost exactly the same.

Balks are down 70% from the '88-89 "year of the balk" spike and aftereffects.

WPs are up 25%, but that looks like an April anomaly - last year they were almost dead even with '89.

Attendance per game is up 9%, and that understates the gains because April is not a good month for attendance. Last year was up about 20% per game over '89.

We talk a lot about strikeouts being up, and some about homers (although I think it's generally missed that we're still nearer historic highs in homers than the historic mean). But I've never seen a discussion about errors being down 30% in that timeframe. And not much on the smaller issues of HBP and intentional walks.

I just did this with pitching numbers, maybe if I get a chance I'll pull some other data off the hitting side of things (although much of it will be the same).

[Don Quixote]

Interesting about the early '90s HBP peak. Did that have anything to do with the transition (which was already underway in some aspects, I think) from tighter-weave, tighter-fitting uniforms to the looser ones that have prevailed over the last generation or so? Was there that much of a difference in style, or am I misremembering? In a way, it's too bad that box scores don't denote the nature of an HBP, whether it's a uniform graze or solid contact.

[DrungoHazewood]

Interesting about the early '90s HBP peak. Did that have anything to do with the transition (which was already underway in some aspects, I think) from tighter-weave, tighter-fitting uniforms to the looser ones that have prevailed over the last generation or so? Was there that much of a difference in style, or am I misremembering? In a way, it's too bad that box scores don't denote the nature of an HBP, whether it's a uniform graze or solid contact.

I seem to remember it as the phase where everyone was wearing body armor and stading on top of the plate. If they got hit, so what? Free base. And it allowed them to drive everything, including pitches on the outer part of the plate.

I don't exactly remember what happened, but didn't they slightly revise the body armor rules 5? years ago, and now it doesn't seem to be a big deal.

[Frobby]

Good stuff! On the 30% reduction in errors per game, I suspect that this is partly due to the way the game is scored, rather than actual improvements in defense. It seems to me, watching games, that over time the official scorers have become more and more likely to give the fielder the benefit of the doubt. I'm not saying that explains the full 30% reduction, but it wouldn't surprise me if 5-15% were due to that.

[DrungoHazewood]

Good stuff! On the 30% reduction in errors per game, I suspect that this is partly due to the way the game is scored, rather than actual improvements in defense. It seems to me, watching games, that over time the official scorers have become more and more likely to give the fielder the benefit of the doubt. I'm not saying that explains the full 30% reduction, but it wouldn't surprise me if 5-15% were due to that.

I wonder if that's true, or if it's one of those constant myths. It was the 1990 timeframe when there was the mini-controversy where Cal made like five errors and year and folks started writing that the official scorer in Baltimore wouldn't give him an error if he threw the ball into the 25th row. I think like much in baseball people have always said things were harder in the old days, and errors are one of those things.

My possibly biased take is that over time errors are tightened up, and that things that used to be hits might be errors now (I'm 100% sure this is true between say 1920 or 1900 and today, just a hunch it's true between say 1970 and today). But running counter to that is better field conditions, better equipment, and more/better/standardized training. Field conditions are a huge one. Just from my youth 20 or 30 years ago to today I think it's pretty clear bad hops have gone down dramatically. Used to be all the time you'd see infielders just flat out misplay a ball that hit some pebble or other imperfection.

[luismatos4prez]

ERA: Up 6%, mainly because...

Errors are down by 30%, from 0.8 per game to 0.55 so far in '13.

What am I missing here? Why would ERA go up as defenses got better?

[thatbearflies]

What am I missing here? Why would ERA go up as defenses got better?

More opportunities to score Earned Runs as opposed to Unearned Runs.

[DrungoHazewood]

What am I missing here? Why would ERA go up as defenses got better?

You know... it probably doesn't have to. I was just thinking runs scored were similar but errors way down, so earned runs had to go up.

[weams]

What am I missing here? Why would ERA go up as defenses got better?

ERA would go up as less base runners were the fault of error, and scored as hits. When they score, they are charged to the pitcher.

[Palmoripken]

Excellent research and very interesting to see how the game has changed from the time I was a newborn to the present. One thing that surprised me looking at your research is that saves have remained constant. That one really surprised me since I thought that in the late 80's with the exception of guys like Eckeresley and a couple of others, there were no really closer types and I can remember Mike Mussina throwing 125+ pitches in the mid 90's a few times. Anyhow, I like how we're seeing a more balanced era. One where teams can and do win with great pitching and D.