The meaning of April

Dave Cameron -- who's writing as much interesting stuff about baseball as anyone around -- on the meaning of April. Money quote:

    Let's use Victor Martinez, as an example. I talked about him whacking the ball in April the other day. He's had a great month, hitting .388/.438/.624 and generally being one of the best hitters in baseball. We can be pretty sure that Martinez won't keep hitting this well, of course, as it is a small sample of data so far.
    However, regardless of what your preseason projection for Martinez was, you should now be quite a bit more optimistic about his performance over the rest of the year than you were on Opening Day. Dan Szymborski released an updated ZIPS projection that accounts for April data (thanks Dan, great stuff!), and ZIPS now thinks Martinez will hit .305/.380/.467 the rest of the season, up from a preseason projection of .293/.366/.447. That small sample size that we're not supposed to get excited about has increased his projection for the remainder of the season by 34 points of OPS. That's a significant change.

    April is only one month of the season. Things won't end the way they are now. We do have to be careful about drawing conclusions on small sample sizes. However, let's not fall into the opposite trap, either - there is useful information to be gleaned from the beginning of the season. Pretending like nothing has changed is just as uninformed as pretending like the current performances will be sustained.

    Don't hang onto your preseason projections like they're gospel. You've got new information in front of you. Use it.

Yesterday in the mailbag, someone asked me when I started looking at run differential, as if there's a particular date when it becomes meaningful.
There's not. For the record, I did glance at the run differentials yesterday, but only because I happened to be looking at the standings for some other reason. The best run differentials belong to the Blue Jays (+40) and the Dodgers (+37). Do those numbers mean anything? Of course they do. Do they mean as much as they'll mean next week, or next month, or at the All-Star break? Of course they don't.

Every day gives us numbers that mean something, and every additional day gives us more meaning. And I think that's especially true when you're talking about a team that's made big changes, or a player like Martinez who's coming off an obviously aberrant season. Everything counts.