Mark Teixeira hasn’t had a good first half. He’s batting .282 with an OBP of .366, figures that are very much in line with his performance the last three years. But he’s only hit eight home runs, compared to 38 and 43 the last two years. As a result, his power numbers are down. On the left graph, you can see the key stat for Teixeira, his Isolated Power. Last year, his Slugging Percentage was fifth-best in the league. This year, his power has been just average.

So, what happened? Well, the first thing to note is that Teixeira’s underlying profile hasn’t changed much at all. For instance, both his walk and strikeout rates are in line with career stats — if anything, he’s improved in these two areas.

When a player’s home run count drops suddenly, you might assume that his flyball rate has dropped, too. After all, pitchers’ home run rates are often a simple result of their flyball rates. However, batters don’t typically change their batted ball profiles very much, and Teixeira hasn’t really changed his this year either, as you can see in this graph:

Teixeira did hit a lot more flyballs in the beginning of the year, but his groundball rate has risen (not a good trend) and his average flyball, groundball and line drives rates are now in line with his previous years. So, what gives indeed?

The simple answer appears to be that he’s not hitting the ball as hard as he used to. Over the last three years, 20% of his outfield flyballs were home runs. This year, he’s at 7%. The good news is that his out rate on outfield flies is holding steady around 77%, which means that last year’s home runs are falling for singles and doubles this year. In fact, he’s tied for second in the AL with 26 doubles; his career high is 41.

Mark Teixeira is the same hitter he’s always been, just less powerful. Perhaps his timing is off, or perhaps pitchers know something about him. Perhaps he’s in a protracted power slump and he’ll turn it around the second half of the year. Perhaps he has a nagging injury. In this age of unsubstantiated rumors, I don’t want to make any other guesses. Let’s just watch and see what happens.

With Albert Pujols on the sidelines, the best player in baseball right now is Carlos Beltran. Beltran is fourth in the league in Runs Created, behind Pujols and two Designated Hitters (Thome and Hafner). Add his excellent glove in center field, and you’ve got the best player currently playing.

Things didn’t go so well for the multimillionaire last year. He batted .266/.330/.414 for the entire year, compared to.300/.408/.643 so far this year. Plus, he’s already stolen 17 bases in 19 attempts, vs. 17 of 23 last year. Improved health has got to be a factor for the Mets’ center fielder, as well as adjusting to New York. Let’s see if we can spot any other details in his peformance graphs.

First of all, Beltran is striking out at a noticeably higher pace this year, higher than at any time in his career.

Strikeouts aren’t necessarily a bad thing, however, if they’re offset by higher walk rates and performance, and Beltran is doing quite well in both categories. His walk rate has spiked this year, and the following graph illustrates that 2005 appears to have been an aberration against a longer trend of increasing walk rates.

Most importantly, Beltran’s batted ball profile has changed dramatically this year. Last year, he hit more groundballs than flyballs, a pattern he had established in three of the previous four years. This year, however, he’s following the same pattern he had in 2004, batting most pitches far into the sky and forsaking groundballs and line drives. On the following graph, flyballs are blue, groundballs are green and line drives are red. I think the changing pattern is pretty clear, don’t you?

The bottom line is a marked increase in Beltran’s Slugging Percentage. In fact, if he were to maintain his pace for the entire year (an unlikely event), it would establish a career high.

Carlos Beltran has become a different type of hitter this year: a swing-for-the fences power hitter with great plate discipline and speed. This is probably a permanent change in style for the 29-year-old — many players have undergone similar changes at this age. If he avoids injury for the next few years, Met fans will not regret that big contract after all.

It’s the latest baseball scandal — Jason Grimsley took steroids, he took greenies, he took Human Growth Hormone. Once diligent steroid testing began (and after he tested positive for steroids in 2003), he quit the ‘roids. But he kept taking HGH, and he’s not the only one. Now that he’s been caught, he’s naming names.

I know it sounds terrible, but I take some pleasure in this latest news. Hasn’t it been obvious that lots of players beside Barry Bonds have taken illegal drugs for years to enhance their performance? Can’t we now spread our ire to the many instead of the few?

This is obviously just the beginning of the next black mark for baseball. In the meantime, I’ve been wondering if we could pick out when, exactly, Grimsley started using the stuff. According to the affidavit, he first took steroids in 2000 to help him recover from Tommy John surgery, but he may have been taking them sooner. Can we pinpoint a date? Did the drugs have an impact? Let’s see. First, here’s a graph of Grimsley’s ERA for every year of his career…

Whoa. Tom Verducci claims that Jason Grimsley was a different pitcher in 1999 and it sure looks like something happened between 1996 and 1999, doesn’t it? Of course, maybe he just got better, or maybe he performed better in relief (he was primarily a starter before 1999 and a reliever afterwards) Let’s take a closer look at some of his component stats. First, strikeouts per nine innings…

If steroids impact strikeout rates, it doesn’t appear that Grimsley’s medical routine had an impact until 2001 and 2002. And even then the evidence is sketchy. How about walks per nine innings?

This is surprising. It appears that Grimsley’s drug routine may have helped him locate the ball better. I’m sure the truth isn’t that simple, but this kind of finding is perplexing. How about home run rates, you ask?

Some evidence, but nothing too compelling here. Steroids and HGH might have helped Grimsley keep the ball in the park but, as a groundball pitcher, he didn’t give up a lot to begin with. For one last clue, let’s take a look at his Batting Average on Balls in Play (or BABIP):

This is, perhaps, most telling. Grimsley’s batted balls were fielded more often, for whatever reason, after 1998. As a groundball pitcher, Grimsley’s BABIP would tend to be above the average, but pehaps he gained an extra measure of movement or speed on his sinker, making his balls more fieldable and giving him more confidence to throw strikes.

This is all speculation, of course. Drugs may have had no impact on Grimsley’s performance at all. Perhaps he was just better suited to a relief role. If drugs did make an impact, it seems that he started taking them before 2000.

Uncovering the impact of performance-enhancing drugs for any single player is not going to be easy.