I have many pet peeves when it comes to mainstream baseball analysis, but one of the biggest is when people can't understand that the good-bad scale is different from the overrated-underrated scale.  The first measures actual talent and the second measures the public's perception of that talent.  For example (and I realize this example is not breaking new ground) Derek Jeter is a good baseball player, deserving of many of his All-Star selections.  But he's also an overrated baseball player, because he's not actually the faultless god many make him out to be -- he's a poor defensive shortstop and his power is mediocre rather than Zeus-like.

I'm going to take the glass-half-full approach today and highlight eight position players who are not only quite good, but who are also quite underrated.  Everyone knows the following names, but they should be mentioned more often on highlight shows and appear on more end-of-season ballots.  Most of them are underpaid.

What makes a position player underrated?  Here's a good set of criteria:

1. Plays in the AL -- NL pitching is weaker, inflating raw stats compared to AL hitters.
2. Plays in a pitchers' park -- currently San Diego, Oakland, Seattle, and Florida play in the more difficult parks for hitters.
   
3. Has a low average and a high walk rate -- OBP is everything.  AVG... not so much.  High strikeouts players are still underrated, too.
   
4. Isn't an RBI guy -- not only do RBIs get way too much press, but "run producers" tend to be out-machines.
5. Plays a difficult defensive position -- catcher, shortstop, and center field qualify as difficult, and the corner outfield spots, first base, and designated hitter definitely do not.
6. Fields his position well -- making an extra play per week is worth as much as hitting an extra dying quail per week (and we're all familiar with what Bull Durham says about that.)

Counting down to the most underrated superstar in the majors (based on my personal judgment of the difference between actual value and perceived value), here are eight players we all know, but don't celebrate enough:

Albert Pujols -- Yes, most people realize he's the best player in the National League even if they won't give him the MVP award.  But what people miss is that he's so far ahead of everyone else.  If you combine Chipper Jones' ridiculously hot first 71 games (.394/.485/.630) with Carlos Delgado's MVP-leading most recent 73 games (.320/.403/.629), the resulting Voltron-performance doesn't quite match Pujols' season line of .348/.453/.631 over 144 games (hat tip, Tom Tango).  And then consider that Pujols is the best defensive first baseman in the game.  If not for Barry Bonds, Prince Albert would probably be the best player of the last quarter century.

Curtis Granderson -- ARod was everyone's clear AL MVP in 2007, but there's a decent argument that Granderson was nearly as productive.  True, he's taken a step back this year from being an all-world defender in center field and his power has dropped a bit, but that merely puts him among the top twenty players in the game instead of the top five (and on a positive note, his plate discipline has improved.)  Going into 2009, I don't think there are ten position players I'd rather have on my favorite team than Curtis Granderson.

Adrian Beltre -- Anyone who still thinks the Mariners' 5 year, $64MM deal for Beltre was a mistake deserves a complimentary colonoscopy.  He's an above-average hitter and an exceptional third baseman (+13 runs per season over the past two).  At three wins on offense and one and a half on defense, Beltre's All-Star caliber performances are worth $18MM on today's free agent market .  His power numbers would be a lot more impressive outside of Safeco, too.

Joe Mauer -- Justin Morneau gets all the love sent in the direction of the Twins' offense -- which appropriately isn't all that much -- but Mauer is every bit as productive with the bat and is one of the top ten defensive assets in the game.  Morneau certainly has more power (and RBIs), but only holds a career .050 point advantage in SLG, which Mauer easily counters with a career .050 point advantage in OBP.  Overall, Mauer's career OPS+ is better, 127 to 122.  Morneau has a slight advantage this year, 140 to 135, but Mauer had the edge in the previous two seasons, including Morneau's 2006 MVP campaign.

Chase Utley -- With his hot start to the 2008 season, I thought Utley might finally get the recognition he deserves.  But with a depressed second half the Ryan Howard-for-MVP talk has again heated up, leaving Utley as the most productive Phillie for three straight seasons and the least appreciated Phillie over that span as well.  Thanks to a Biggio-like ability to get hit by pitches, his career OBP is .375 and it's not easy to find a second baseman who can slug .525.  Now add an Ozzie-like glove to that offensive talent and you've got Utley.  Ok, that Ozzie comment might be a slight exaggeration, but when a single player can claim to be both the best hitter and the best fielder at his position, he's something special.

Grady Sizemore -- Just like Albert Pujols has been the clear-cut best National League player, Sizemore takes on that role in the national league.  His raw rate stats can stack up to everyone outside the likes of ARod, Milton Bradley, Kevin Youkilis, Carlos Quentin, Aubrey Huff, and Nick Markakis, and his high plate appearance total closes the gap.  But none of those guys can come close to Sizemore's defensive value, vaulting him ahead by over a full win.  All of his first four full seasons have been remarkably similar in value, too.

Brian Giles -- The greatest trick the devil ever pulled was convincing the world he didn't exist.  Giles' trick of convincing baseball fans he's somehow not a superstar is pretty interesting as well.  A raw line of .304/.396/.449 is pretty sweet (you did notice the near-.400 OBP, right?), but it's awesome coming in PETCO, which reduces run scoring by one run per game per team compared to a neutral park.  Translating Giles' performance into 4.6 RPG environment makes it look more like .322/.415/.473, which is of similar value to a .322/.365/.553 line (trading OBP for power.)  Oh, and Giles' glove has averaged +10 runs in right field over the last two years, making him as valuable defensively as the average center fielder.

Carlos Beltran -- Carlos Delgado, David Wright, and Jose Reyes receive more credit for the Mets' success this year, but there's a good argument that Beltran has been the National League's MVP.  I can only think of one thing Beltran doesn't do significantly better than the average player, and that's hit for average.  He walks, hits for power, is a stud baserunner, plays center field, and is a Gold Glover out there.  Defense is probably the most underrated skill in baseball right now, and guys who do everything well instead of doing one thing extremely well tend to fly under the radar.  If you know a Mets fan, tell them to stop expecting Beltran to live up to his $18MM-per-season contract and realize he's performing like a $25MM stud.