Validity of first-half vs. second-half numbers

[Mean Linguine]

I think we established in an earlier post that you'd need at least a full-season's worth of at bats, maybe even multiple seasons, for something to be statistically valid.
But the other day I was reading about Paul LoDuca, and they were talking about how over the last three years he hit around .300 in the first half of those seasons and around .250 in the second half. Guess the answer is just to play him for the first 81 games and sit him for the rest of the year! No, seriously, how much stock do you guys put in first-half and second-half numbers by themselves? In LoDuca's case, is that a trend, or just a statistical fluke? It always amazed me how guys like Bernie could tear up spring training, then go back to his "usual slow start" in April. Makes you wonder if it's psychological more than physical.....

[boo_427]

Kinda along the same lines...

Jeff Francouer: http://www.baseball-reference.com/f/francje02.shtml

Until he proves it over an entire season, there will still be detractors.

Some guys start hot, some finish it.

[Wang's Groundballs]

I'm not sure how I feel about 1st half vs. 2nd half numbers. For the most part I think how a player performs in a certain month or half of the season is just random, and all that matters is how they perform overall because that's really all you can use to predict their future with.

At the same time, however, I do believe there are players like LoDuca who "break down" by the 2nd half, which is why, especially at the time, I thought the Dodgers made a very good trade when they got Penny and Choi.

So I guess I can't really give you a definite answer. When predicting future performance I wouldn't place any more emphasis on 2nd half numbers for a player -- like say, Bobby Abreu -- then I would their overall numbers; unless of course they were injured one part of the season or another legimate reason to believe that time period in no way represents their true talent level and that that "event" is unlikely to occur again.

[Mean Linguine]

Kinda along the same lines...

Jeff Francouer: http://www.baseball-reference.com/f/francje02.shtml

Until he proves it over an entire season, there will still be detractors.

Some guys start hot, some finish it.

That guy almost looks like a Shane Spencer. Pretty impressive numbers for 70 games.

[Mean Linguine]

I'm not sure how I feel about 1st half vs. 2nd half numbers. For the most part I think how a player performs in a certain month or half of the season is just random, and all that matters is how they perform overall because that's really all you can use to predict their future with.

At the same time, however, I do believe there are players like LoDuca who "break down" by the 2nd half, which is why, especially at the time, I thought the Dodgers made a very good trade when they got Penny and Choi.

So I guess I can't really give you a definite answer. When predicting future performance I wouldn't place any more emphasis on 2nd half numbers for a player -- like say, Bobby Abreu -- then I would their overall numbers; unless of course they were injured one part of the season or another legimate reason to believe that time period in no way represents their true talent level and that that "event" is unlikely to occur again.

Is three season's worth of second half numbers enough to make a conclusion, if those are three consecutive seasons?

[Snatch Catch]

I put additional stock in those breakdowns because LoDuca is a catcher. It stands to reason that he would be more open to wearing down due to the additional physical stress of being a receiver.