Carlos Pena led off last night. Carlos Pena led off for the first time in his career last night. Carlos Pena led off, despite averaging about two stolen bases per season and going against one old-school adage (speed at the top!) even as he fits another (second basemen bat second!).

Just how rare was the occurrence, though? And given the current state of the Rays, was it a good idea?

In the history of baseball, 273 first basemen have led off a game. In the past 10 years, a first baseman has led off 306 times. Corey Hart already managed the feat this year. Doesn’t seem so rare now, right?

But wait. Kevin Youkilis led off as a first baseman 90 of those times. Brad Wilkerson did it 76 times. Scott Hatteberg did it 38 times. Not only is this lineup arrangement getting rarer as we look deeper into it, we’re seeing a pattern emerge. Moneyball taught us this trick. If you don’t have a speedy guy who can take a walk on your roster, then throw a slow guy who can take a walk in the spot. More than half of all the instances of first basemen leading off fit this pattern. So does Carlos Pena.

The strange thing is that this Rays team has other, speedier, options for the leadoff spot. For one, there’s Ben Zobrist. He’s walking more than Pena right now, and he’s been above-average on Bill James‘ speed score his entire career. You can make an argument that he has some power and could be useful in the middle of the lineup — perhaps to break up some lefties — but with Desmond Jennings healing, Zobrist would be the natural choice for the top of the order.

But Maddon isn’t making this choice for the long-term needs of his team. He’s focused on the short-term needs of one player.

Hitting Los leadoff. We’ve tried it with a few other guys and it worked. I want him to accept his walks, think of himself as a tablesetter. — Joe Maddon (@RaysJoeMaddon) May 22, 2012

Maddon has done this before. He tried it with Evan Longoria. He once mentioned that he would have done this sort of thing with Albert Pujols. In fact, he’s been doing it his whole managerial career:

“I did it with Tim Salmon in the minor leagues. I did it with another player you’ve never heard of; his name was Kevin King, had great results at Double-A. These are big, strong guys that you normally wouldn’t see in the leadoff spot. I explained to Longo I wanted him to go out there today, work good at-bats, get on base, use all of his baseball skills and help us win a ballgame. And really try to give him a different outlook. Hopefully he’s going to have some fun with it and see where it takes him.”

So now, with Pena showing the second-worst strikeout rate of his career and the worst isolated power number of his career, Maddon is trying something new. By focusing on getting on base, Maddon might remove the power question from his first baseman’s mind. After all, even a struggling Carlos Pena is on track to be worth more than two wins — which would make up about half of Casey Kotchman’s career win contribution. Perhaps this is to remind Pena that he still has an elite skill. Perhaps it’s even a one-game anti-shift move, with the side bonus of lauding Pena for something he’s doing right.

The one game sample seems to say the move was a good one. Well, maybe. He hit a home run, and it was the power that was lacking. Strangely, he didn’t take a walk, struck out once, and left two on base, but he did hit that home run. In any case, the team won and Pena probably felt fairly good about the game.

And in any case, this was a move rooted in psychology. Any study of players being moved to the leadoff spot during slumps would be fraught with sampling issues, and a saber-savvy manager like Maddon knows it. But Maddon also knows his players, and if he believes a move like this can clear a slugger’s mind, it’s worth more to him and his player than the one-tenth of one run that he might lose by putting his slugger at the top of the lineup.

As little as a single-game lineup change may mean, we can’t just poo-poo this away without some kudos for non-linear thinking. For all this talk of how often it’s happened, it is fairly rare to see a first baseman bat leadoff — after all, it didn’t happen once last year, and the last time it happened before that was… Dan Johnson in 2010.