It matters

The Braves have swept the Nats and now lead them in the standings by four games. We’ll hear the standard bromides: it’s still early April; early season standings don’t mean much; there’s still plenty of time to make it up. While there is certainly some truth to these platitudes, the reality is that what’s happened in the last two weeks, and especially in the last three games does have a significant impact on the Nats’ playoff odds. It matters.

We can think about each win or loss having two kinds of significance. There’s the direct significance: The Nationals are now four games behind the Braves. To win the division, over the remaining 150 games they will now have to win five more than the Braves win. Since the Braves are obviously pretty good, that’s a lot tougher task than the task we faced two weeks ago—to win one more game than the Braves over 162.

Then there’s what Bill James, writing about this topic way back in the 1985 Bill James Baseball Abstract, called the “signature significance”: The fact that the Braves have started the season 11–1 is an indication  that the Braves are  an unusually good team, probably better than we thought they were at the beginning of the season. That’s true, even though 12 games is a small sample, because it’s far more likely that a really good team will go 11–1 than an average team. He gave the example of a pitcher striking out 15 batters in a game without walking anyone. Even though we normally would never evaluate a pitcher based on a single game, such an extreme performance signifies that this is an unusual pitcher. An average pitcher like Livan Hernandez or Jason Marquis might occasionally have a very good game, but not that good.

I’m aware of two websites that provide playoff odds that are updated daily, and they often give very different results, especially during the first half of the season. My understanding is that Baseball Prospectus gives heavy weight to its projections of the strength of each team, which I believe are based on projected performances of the individual players on the team. When its odds are updated each day, you are mostly picking up the direct significance, because their projections of team strength are adjusted very gradually. With each Braves win this weekend, their playoff odds have increased 4 to 5 percentage points, with the Nats declining by a similar amount.

The other website is coolstandings.com. My understanding is that it bases its playoff odds entirely on what’s happened this year to date, so it’s pretty much at the opposite extreme from Baseball Prospectus—it’s giving an extremely large weight to the “signature significance” of the games won and runs scored by each team. One thing that’s nice with their web site is that it allows you to select the date, so you can look back at how the odds have changed day by day. In the last three games, the Nats’ playoff odds have dropped by 16-1/2 percentage points, from 48.6% to 32%. (At the time I’m writing this, Baseball Prospectus hasn’t updated their odds to include today’s game, but I’m guessing that it will come in about 55%, representing their still fairly strong evaluation of Washington’s talent.)

My point isn’t that we should abandon hope – the platitudes about the long season are certainly correct that a three-game sweep early in the season can easily be reversed later in the season. But it’s definitely the case that the Nats have dug themselves into a bit of hole and it may be tough to dig out. It will be critical that the next time they face the Braves, they will need to play better and win some of the remaining series between these two elite teams.