Well, as far as the MVP is concerned, among NL hitters it’s Pujols and then daylight right now.
As you point out, he leads comfortably in homers (10 ahead of his nearest rival) and OPS (over 150 points ahead). He’s also second in the league in average (.334, not .364), and is only 13 points behind Hanley Ramirez in that category. He has only 3 more strikeouts than home runs. He has 73 walks (including over 30 intentional, plus a whole lot more where the pitcher was so careful that he never even got a chance to hit the ball). He even has a better stolen base record than most of his nearest competitors (10 SB, 3 CS).
Comparing hitter to pitchers using regular stats (AVG, SLG, ERA, Wins, WHIP, etc.) is more difficult, because you’re talking about different types of contribution.
One possibility here is to compare a stat like WARP, which measures the number of wins a player contributes above a replacement player. Based on performance so far this season, Pujols is actually behind Arizona’s Dan Haren. Haren’s WARP1 (WARP for games played so far) is 8.7, while Pujols’ is 7.7. Their WARP3 figures (which extrapolates the figures to deal with a full season) are 13.6 and 12, respectively.
Of course, the title you’re asking about is Most Valuable Player, not Player With Highest WARP, and not even Best Player.
Many MVP voters seem to feel that a crucial aspect of determining a player’s value is the overall performance and final position of his team. So, if a team manages to win a division, or even just scrape into a playoff spot, a top player on that team is more likely to win MVP than an equally good player on a team that misses the playoffs.
I really think that there are some voters who, faced with a player who hit .350/.450/.700 with 50 homers while playing for a losing team, would not consider him for MVP.
Given that the Cardinals are in first place, and seem likely to stay in the hunt for a playoff spot over the next few months, while the D-backs are 13 games under .500 and look very unlikely to contend, this would seem to work in Pujols’ favor.
Also, however you calculate value, it seems to be very difficult for a pitcher to win the award. By my count, over the past 30 years, only 4 pitchers have won the MVP in all of Major League Baseball (both AL and NL), and all four of those were in the American League. The last time a National League pitcher won the MVP award was 1968, when Bob Gibson won for his incredible season.
I’d be interested to see if figures like WARP suggest that more pitchers should have won, but i don’t have time to check right now. It could be that, with the presence of a special award for pitchers (the Cy Young), voters tend (consciously or subconsciously) to favor hitters for the MVP, even if a pitcher has put in a better season.