Saturday, April 3, 2010

Spring Training Nears An End - The Coors Field Effect Part III

Greetings readers! Ryan Spilborghs' Beard here, the bearer of bad news from Arizona. Well, from New Mexico, actually... but no matter which state it's from, it's bad news... Jeff Francis had some soreness in his arm yesterday. What's worse, it's the arm he throws a baseball with, and he will therefore start the season on the DL. As a Beard of nearly unlimited power, I will do everything I can to hasten his healthy return to the field.

And now, time for your silver lining: Francis will be replaced in the rotation by Greg Smith. Now, while it's certainly not a good thing when your #2 starter, returning from major arm surgery, goes on the DL, but when you can replace him in the rotation with a guy who posted a 1.50 ERA this spring, that's pretty nice. Candidates to fill Smith's bullpen spot appear to be Joe Beimel, Justin Speir, and Tim Redding.

Look for a season preview tomorrow, but first, some old business to attend to: the final installment of The Coors Field Effect. Part III will deal with how the CFE is percieved today, and how it affects the reputations of current and past Rockies.

THE COORS FIELD EFFECT: PART III
This Time, It's Personal!!!

Even with the humidor in place, there is no arguing the fact that Coors Field is one of the best hitter's park in the Major Leagues. Park factor numbers over the park's history indicate that while it's certainly beneficial for Rockies hitters to play half their games at Coors Field, it is not the same park today that it was during the first seven years of its existence. As the Rockies gain national attention, this reputation is slowly changing, but it has taken a lot of time.

Rockies fans know better, of course, but the perception among many fans and ill-informed sportswriters leaguewide is that Coors Field is still a launching pad that makes All-Stars out of merely decent hitters. For example, when Matt Holliday was traded, the bulk of baseball fans and experts believed that his numbers were the result of hitting at Coors, and he would not be successful on another team. His struggles in Oakland appeared to support this notion, but then he went to St Louis and put up numbers (over half a season) which were even better than he ever did as a member of the Rockies. He got the big, fat contract he wanted, and maybe, just maybe, people started to realize that a great hitter at Coors Field may actually be a great hitter, period.

So the reputation that Coors Field creates good players from lousy ones and All-Stars from good ones is dying -- too slowly perhaps, but it is on its way out. There is one thing which remains, however, which baseball fans (both casual fans and those who should know better) still focus on: despite the humidor, there is a large gap between the home and road stats for most Rockies hitters. In nearly any discussion about a Rockies hitter, past or present, somebody will bring up "home/road splits," in an attempt to prove that the player is a Coors Field creation.

It is true that most Rockies batters, even post-humidor, have much higher numbers at home than they do on the road. Using Holliday’s 2007 season as an example: he hit .340 that season; which broke down to .376 at home, and “only” .301 on the road. It is widely believed that this gap alone cost Holliday the 2007 NL MVP award, despite leading the league in average, RBI, hits, doubles, and total bases (all of which, his detractors point out, displayed similar home/road splits as his batting average).

The numbers do not lie. Even though large differences in home/road splits are not uncommon for players who call other hitter's parks home, nowhere are they as drastic as in Coors Field. The implication, then, when fans say “look at his splits” is that Holliday is actually a .301 hitter, not a .340 one, and that hitting half his games at Coors Field added about 40 points to his total average.

This is an all-too-common assumption, but it is a lazy one. Indeed, the numbers do not lie, but without an understanding of what creates them, they can certainly be misleading. There is evidence to suggest that hitting at Coors Field for half the games in a season actually hurts a player’s road stats. We will look for that evidence by ignoring home-park statistics, and by comparing only road numbers.

Rockies fans know that the Rockies often struggle on the road, but just how badly they have hit on the road may come as a surprise. In the ten seasons from 2000 to 2009, the average road batting average for all NL teams was .261. The Rockies’ road average during that decade was .244. Within that ten-year span, the Rockies’ best-ever year hitting on the road was 2007, when they hit .261, good for 20th in the majors. The remaining nine seasons, their ranking among all major league teams in road batting average reads like so: 26thtwice, 28th four times, 29th once, and 30th twice. That's nine of the last ten seasons in which the Rockies have finished in the bottom five in all of baseball for road batting average. Something is amiss.

Now, there are those who will answer that by saying that the Rockies have been a losing team over that span of time, and their lineup is commonly made up of lousy hitters who only look decent because they play at Coors and are only showing their true colors on the road. As any Rockies fan will tell you, the team wasn’t exactly successful until the past 3-4 years, but rarely have they been flat-out bad. The Rockies during this decade had two 90+ win seasons, one 80+ win season, and only twice did they fail to win at least 70. As a comparison, let's look at a team that's had a truly miserable decade: the Pittsburgh Pirates.

Over the last ten years, the Bucs lost 90 or more games seven times, barely missing that mark twice more with 89 losses, and only three times did they break the 70-win mark... yet their average road BA over that time was .251, seven points higher than the Rockies'. In 2009, regarded as the Rockies’ best-ever regular season, the team hit .235 on the road; the Pirates, losers of 99 games, hit .234. So while their win/loss results do not suggest the Rockies would be at the top of the league for road BA, they are certainly much lower than we should expect from a team that has played decent-to-good baseball for much of the last decade.

So, what makes it more difficult for the Rockies to hit on the road? If we can assume that the Rockies had, at the very least, average hitters over the last decade, then why are their road numbers so much lower than the league averages? The answer is fairly obvious, really, and it goes back to the physics at work at Coors Field.

Hitting is all about timing: you see the ball come out of the pitcher’s hand, you anticipate what pitch is coming, and you swing at it. If your timing is right, you make good contact and you might get a hit. At Coors Field, we already know that due to the altitude, breaking balls do not break as much as they do elsewhere. Even with the humidor helping to minimize this aspect, physics tells us that breaking pitches are less effective at Coors Field, so a pitcher must either choose to continue to throw breaking balls that don’t break as much as he would like, or to rely more heavily on his fastball… either way, he’s doing the batter a favor.

After a week or ten days seeing those kinds of pitches, however, Rockies players must pack up and go on the road, where all of a sudden, a curveball or slider breaks 25% more than it did in Denver. The timing he's relied on at Coors tells him when and where to swing, but the ball isn't where he expects it to be. He either strikes out, hits a weak grounder, or pops it up... all because the timing used to hit a ball at Coors Field doesn't translate to hitting on the road.

It is vital to note that this is not a problem Coors shares with other hitter's parks. Other hitter's parks are made so by the dimensions of the field, the foul territory, the height of the fences, etc. At Coors Field, all these things come into play also, but the one factor that is not present elsewhere is the behavior of the breaking pitch. No other team's hitters struggle with the ability to make contact on the road like the Rockies do, because no other team's hitters have to adjust their timing each time they travel. The Rockies' situation is unique, making the application of standard logic to their park factor and their home/road splits inherently unfair.

Do the Rockies' road numbers support this theory? A quick look at strikeouts is a good start: the Rockies strike out much more on the road than at home. On the surface, this is what we would expect, because we know that Coors Field is a good place to hit. The important thing, though, is this: when we eliminate home stats and focus only on what teams do on the road, we find that the Rockies strike out at at a higher rate than the average team. Since the introduction of the humidor, the Rockies on the road have struck out about 14% more often than the NL average. Again, assuming the Rockies are at least average hitters, their road numbers should be average, but once again, we see this is not the case.

The definitive statistical proof of the negative Coors Field Effect would be to examine offensive stats for each day of Rockies road trips, taking into consideration the length of their previous homestand. My hypothesis is this: Rockies hitters, particularly after long homestands, will be found to strike out more often, and have lower hitting stats overall, during the early days of a road trip. As the trip goes on and they get away from their Coors Field timing, their BA and other stats will go up, to the point where near the end of the road trip, they should be hitting close to the league road average. If such a correlation is found, it would be a clear indication that the Coors Field Effect actually hurts a Rockies player's performance on the road.

If the numbers indicate that hitting at Coors Field creates a disadvantage for the Rockies when on the road, is it fair to use road performance as a base, or control number, as is done currently? Clearly not... if road games are not neutral ground stats-wise, then not only are the current park factor adjustments and home/road splits analysis inherently unfair to Rockies players, but the current overall park factor (which is computed by comparing home production to road production) for Coors Field is also inaccurate.

What can be done, then, to view Rockies player's stats and accomplishments in an objective matter? The quick answer I will propose is this: when looking at a Rockies hitter's home/road splits, boost his road numbers by 15% (I arrive at 15% based on the 17% dip in road BA and the 14% increase in road strikeouts when compared to league averages). After this adjustment, we will see that the gaps between a Rockies player's home and road stats, while still evident, are closer to what we find in other strong hitters' parks, such as Fenway.

As an example: Todd Helton is a career .328 hitter. His home career batting average is .361, his road average .294. Nobody who's seen Helton at the plate throughout his career thinks he's a .294 hitter, not even close. If you adjust his road average by 15 points, he’s at .309, which still leaves a 52 point gap between his home and road stats. But before you make a big deal about that number, consider that Wade Boggs, also a career .328 hitter, had a 52 point gap in his home and road splits, and he easily made the HoF in his first year of eligibility. Yes, there's a difference between Helton's home and his road production, as there is with most any Rockies player. That differnece in a player who played at another ballpark, though, is rarely an issue at all, but it is a huge issue if the player called Coors Field home. The whole point behind this essay is that it shouldn't be.

CONCLUSION

Is the Coors Field Effect real? Yes, but it is not what it once was. There are certainly some factors at Coors Field -- some unique to the park, others not -- which make it a very good hitter's park, but the humidor has done much to lessen these factors, creating a place where real, well-pitched baseball games are commonplace rather than exceptional. Coors Field is a hitters park, and it always will be, but the days where it was head and shoulders beyond any other park are long gone.

The reputation, however, remains, and it has made it difficult for Rockies hitters to ge the respect they often deserve. Home/road splits are often used to minimize the achievements of Rockies hitters. However, these, and other sabrmetric efforts to mathematically neutralize all statistics for park factors, are actually inherently unfair to the Rockies, because of the false assumption that road games are even and neutral territory for all players.

This must change. The Rockies' success on the field is altering the common opinion of Coors Field itself, but the flawed and unfair reasoning many fans and so-called experts use when viewing a Rockies player's stats is still prevalent. This logic has made it difficult for Rockies players to be recognized for awards such as the MVP (Helton in 2000, Holliday in 2007), and is already being used in discussions about the Hall of Fame worthiness of Rockies players such as Larry Walker and Todd Helton.

These kinds of fans do not trust their eyes, they only trust the numbers; and so, until Rockies fans can arm themselves with the facts and the numbers proving that Coors Field, in spite of gaudy offensive stats and large home/road splits, no longer bolsters a hitter's stats any more than any other hitter's park, then the reputations of Rockies greats past and present will continue to suffer.

3 comments:

Some Guy said...

Hey Dr. Brainsmart,

I'm not clear on how you ended up with the 15% adjustment to the Rockies' hitters' road splits. You said that you "arrive at 15% based on the 17% dip in road BA and the 14% increase in road strikeouts when compared to league averages." Does that mean that the difference in the Rockies' home/road stats is 15% wider than league averages, or just that their road stats are, generally speaking, about 15% lower than the rest of the league's?

Don't get me wrong, I agree with your premise, but could it be argued that Coors Field still helps Rockies' hitting more than being away from Coors hurts it? That, say, Helton may be better than his .294 road average, but not quite as good as his .328 overall average?

I wonder if anybody's looked into how opponents' batting stats at Coors Field compare to their away-from-Coors stats. There wouldn't be as much info to work with from any individual player, but overall, obviously, there have been just as many "away" games played at Coors as there have been home games. If, say, your average non-Rockie .328 hitter hits .361 at Coors Field, that'd suggest that Helton's overall .328 average isn't artificially inflated.

Some Guy said...

Also: the little sad pirate picture made me surprisingly sad.

Dr Brainsmart said...

Some Guy, the 15% is a number I chose as a middle point between those two other numbers, which compared only the Rockies' road averages to the road averages for the rest of the league. So yes, it's a semi-guess at how much lower the Rockies' road numbers are than they would be if they played their home games at a park which didn't mess with their swing and timing so badly. It does not look at home/road splits in total, or consider home-park statistics, period.

Basically, it's an attempt to present Rockies' home/road splits, which are still pronounced even post-humidor, in a more accurate light. Home/road splits assume that (and are universally used as if) the road is more-or-less neutral territory for all hitters, and that the home/road split indicates how much a hitter benefits from his home park. I believe the historical stats will show that it is, in fact, not neutral territory for the Rockies hitters, therefore making the use of home/road splits to evaluate a Rockies hitter inherently unfair and inaccurate.

I do think that Coors helps a player's overall stats more than it takes away from them on the road, but the road issue does take away much of the perceived home-park boost that Rockies players get... enough, in my opinion, to allow Coors Field to be viewed as nothing more than any other hitter's park.

The argument at the end of it all is something like this: Helton's .328 career average is no more suspect than Wade Boggs' .328. Both men took full advantage of hitter-friendly parks, but few question Boggs' ability. They shouldn't question Helton's, either.