Comparing hitting across generations: neutralized hitting

I hate winter and everything about it. I hate cold, snow, ice and bulky clothes. My least favorite day of the year happens to be today (Sunday), the first day after the time change when we lose an hour of sunlight at the end of the day, and I don't care that Daylight Savings Time is a man-made invention. I don't ice skate, ski, snowmobile, cross-country ski, play hockey or curl. This is why I live in Iowa.

One great aspect of winter is it gives me time to research baseball's past. Most of my posts for the next month or so will be Hall of Fame-based -- not because I consider the Hall to be the ultimate shrine and symbol of a player's career, as much as a way to view a player's career and see how well he stacked up, not only to his peers but to the best players in history.

Context is the most important thing to me when reviewing players -- did what a player accomplish really set a standard, or was he just part of overall historical trends? Batting averages and home run totals rise and fall, and it helps to have a yardstick with which to compare careers. One of the backwaters at Baseball-Reference allows users to neutralize a player's career stats to different eras, and even different parks. This provides one way in which to put Barry Bonds and Babe Ruth on a relatively equal footing to see how they compare.

This chart shows the average number of runs per game throughout baseball's history:

As fielding improved, errors -- and thus unearned runs -- decreased, such that by the time the American League was formed in 1901, teams were scoring around five runs per game. The Live Ball Era that began in 1920 wasn't as much a lively ball as a cleaner one, one not covered with spit or mud and scratched with every device pitchers could find. A cleaner ball was easier to see and hit. There were ebbs and flows over time, and currently there's been a sustained decrease in offense since around 2007, with average runs per game down 4.07, the lowest since the strike-shortened 1981 season. What's causing it -- better pitching? Worse hitting? The answer, of course, is yes, and many other factors as well.

Using neutralized hitting places all hitters in the same context to see who were beneficiaries of when and where they played and who were penalized. This first table shows players who were most hurt by playing in the wrong place, time or both:

RC=runs created   Actual values are on left, n indicates values in a neutral stadium in the 2014 run environment (4.07 runs/game). dRC=percent difference in runs created. Click here to see how these values are calculated.

My primary measure is runs created, a Bill James invention. As the first chart showed, runs have always been scored, it's just how that changes. I was looking for the difference in actual runs created as opposed to how many runs would have been created had the player played in a neutral hitting park in 2014. Using Deacon White as the example, he created 901 runs in his career, but had he played his career in Camden Yards (very close to a neutral park) in the 2014 run environment, he would have created 1,291 runs, a 43.3 percent difference.

All these players played in eras or conditions that featured less offense than in 2014. In addition, neutralizing everything to a 162-game season will make for dramatic increases for the 19th Century players. Steve Garvey, Frank Howard and Tommy Davis all played during the mini-Dead Ball Era of 1961-1968, played many games at hitter-unfriendly Dodger Stadium, or both.

We really don't care all that much about players from 100 years or so ago, since no one alive saw them play, and even if they did only saw a fraction of the players. This table shows players whose careers began in 1970 or later:

There are a number of players who played a significant number of games in hitter-unfriendly parks such as the Astrodome. Most of these players were near the beginning of this time span because offense started creeping up around 1980.

There's usually no greater meaning other than to note that when making cross-generational comparisons between players ("Ty Cobb didn't hit near the home runs as Ken Griffey Jr. -- how can you call him one of the greatest center fielders ever?"), the context in which they played needs to be taken into account. In that example, Griffey was credited with 1,994 runs created, and if he had played all his game in a 2014 neutral park run environment, would have created 1,832 -- among the best of his generation. Cobb's numbers are 2,517 (actual) and 2,664 (neutral) -- among the best ever. Context matters.

So who benefited most from when and where they played?

It's no secret Coors Field is an extremely friendly hitting park, and the numbers bear out the advantage Todd Helton and Larry Walker (and to a lesser but still significant extent, Vinny Castilla and Dante Bichette) had in playing half their games in that launching pad. There were, er, other issues that made the period from 1995-2007 among the most robust offensive periods in baseball history, which is why players from that time frame are liberally represented. I expected to see players from the 1930s, but was surprised by the number from the 1880s -- I always forget that just because they didn't hit home runs, didn't mean they didn't score runs.

In my future posts, I'll introduce other ways to evaluate the current crop of Hall of Fame candidates, as well as evaluate past selections. This can help place players in context of not only their peers (the primary consideration), but for all historical players. In general, I believe it's unfair to compare players to those of past generations, because conditions are too far different. I'll go even further in stating about as far back as I'll go in pitcher comparisons is around 1950, but I'm getting ahead of myself. It's these kinds of issues that need to be thoroughly investigated as Hall of Fame discussions come around.

It was 24 degrees when I left the house Saturday morning for Bible Study, too cold for November 1st. The day I fear will be in a couple of months when I say to myself "High of 20 -- hey, not bad!", because that's the sign I've officially given in to winter. But I'll have baseball to write about, which will give me great solace. Now if it could only get the snow off my driveway.

All data from Baseball-Reference. Any mistakes in compiling or amalgamating the data are the author's. To see more of the data, go to this Google Docs spreadsheet. A Tableu data viz can be seen here, and is also linked to the spreadsheet.

Scott Lindholm lives in Davenport, IA. Follow him on Twitter @ScottLindholm.