The Rockies are off to a hot start. We've heard that line before--in 2011 and 2013, to be precise. Those hot starts were followed by ice ages of Precambrian proportions. So after getting burned twice by hot starts, Rockies fans should be understandably nervous. Is the bottom going to drop out of this season like it did in seasons prior?
Wins and losses can be fickle things; dozens of events go into the great fondue of a baseball game, and at the end of play it's either an "L" or a "W." But there are better ways of predicting the future than simply looking at winning percentage and projecting it forward. Have the Rockies "earned" their 22-15 record (that's a .682 winning percentage)? Let's look at the ingredients of the Rockies' season so far.
This is the quick and dirty measurement that even non-Sabermetricians like to look at. Baseball is about scoring more runs than you allow; whaddaya need, a road map? Wins and losses are so dependent on sequencing that simply looking at aggregate runs strips a lot of the noise away. A team that wins a game 10-0 one day, then loses 5-4 the next, probably played better than the opposing team, even if their records are identical. So how do the Rockies stack up?
Yep, the Rockies have the best run differential in baseball, plus six on the Athletics and plus nineteen on the nearest NL team (the upstart Miami Marlins). All those blowouts contributed to the Rockies' gaudy run total. By this measure the Rockies have actually UNDER-performed. They have allowed the fifth most runs in the league, but when you factor in Coors Field, that's actually pretty solid run prevention. Naturally, they lead baseball in runs scored by a mile. Also, lol Diamondbacks.
But runs scored isn't the end-all-be-all either. As Dave Cameron of Fangraphs explains in an earlier piece on the subject, runs scored can be misleading as well. Runs are as susceptible to the vagaries of sequencing as wins; a team can go 0-15 with runners in scoring position and score fewer runs than a team that gets one or two timely hits.
So let's compare some other stats and see what the Rockies have been doing against their opponents.
Average and BABIP Differential
|Team||Avg Diff||Team||BABIP Diff|
|Red Sox||-0.004||Red Sox||-0.005|
The Rockies once again lead the way, this time in (Batting Average-Batting Average Against) and in (BABIP-BABIP Against). Remember, home park has nothing to do with this one; Rockies opponents have hit in the exact same parks as the Rockies themselves. Highly correlated with this, the Rockies far outstrip their opponents on balls in play.
By almost all measures, the Rockies have been far outhitting their opponents, while pitching at about a middle of the pack rate (101 ERA-). Nothing suggests this offensive outburst has been "unearned;" however, it is fair to speculate if it's unsustainable. The components of the Rockies' hot start are commensurate with their performance. If Tulo stays unbeatable and the pitching survives, there's no reason why the Rockies can't keep pounding opponents into submission.