Who's got 'Momentum'?

Creating a list of the top 100 hitters according to how they have performed to date is a fairly simple task. By comparing the statistics of every player in each of the five standard hitting categories -- batting average, runs scored, home runs, RBIs and steals -- as the ESPN Player Rater does, you can easily see how each player's 2010 performance thus far stacks up to the rest of the league. However, when it comes to predicting how hitters will rank for the remainder of the season, the task is far more challenging.

Consider Miguel Cabrera, currently ranked No. 3 overall on the ESPN Player Rater. There's no doubt Cabrera has been a standout performer consistently throughout the season, and yet in each month, there were a few players who one could reasonably argue had more fantasy value. Here are his month-by-month splits, along with a list of players who were "better" for the length of each calendar page:

Even with a batting average close to .400 in July, there were still a pair of players who did even better over that particular segment of time, but as you can also see, not a single player topped Cabrera twice this season. That's why though he was never the absolute best player for any month of 2010, overall he remains surpassed only by the Texas Rangers' Josh Hamilton and the Tampa Bay Rays' Carl Crawford, and the latter only because of the outfielder's stolen bases.

The ESPN Player Rater is strictly a comparative tool, so being "far better" in a given category than the "average player" earns you a higher rating than being "a little bit better." Crawford, second in the majors to Juan Pierre in steals, gets 5.67 points in that category. There are far fewer steals to go around than home runs, which is why Jose Bautista earns only 4.15 points for leading that particular category.

In many ways, it's a counterintuitive system, because Crawford's value in steals -- and thus his overall value -- actually is slightly lower as a result of Scott Rolen having stolen a single base, yet Rolen's rare feat (for him, anyway) has zero impact on Crawford's ability to steal bases going forward. That's why we need a second metric to balance the value of each individual stat along with each player's skill set and individual ability to hit for average, hit for power, run the bases, etc.

That's where my own creation of "Momentum" comes in. It's a complicated formula that attempts to combine the value-based ranking of accumulated stats with a skills-based ranking that tries to measure a player's future performance in the absence of "lucky streaks" or having other players' successes or failures impact their own personal evaluation.

A number close to zero indicates that a player is performing exactly as expected so far in 2010. As the Momentum value gets more positive, it exposes the underachievers, those whose talent levels have not lived up to the fullest potential. These players have the most room for growth for the rest of the season. As Momentum gets more negative, it weeds out the overachievers. For these players, it is far more likely that their performance to date has been a bit of a mirage and a correction in the opposite direction may be on the horizon. Here's a list of a few of the players with the highest Momentum numbers (through Sunday's games):

Keep in mind, the underachiever tag is not necessarily a bad thing. For Drew Stubbs, in the midst of a 1-for-34 streak with 16 strikeouts, it certainly speaks to disappointment and growing rumors of being sent back to Triple-A. But in the case of a Nelson Cruz or a Brett Gardner, it simply means that their current rankings are far from a fluke, and even better days are still to come.

Similarly, being an overachiever doesn't mean you're doomed to failure; it merely means the odds may be stacked against you, as in the case of Marlon Byrd, whose career batting average of .284 speaks to a likely regression, or Martin Prado, who just landed on the disabled list, which certainly will impact his playing time going forward. In Joe Mauer's case, it has more to do with being at an equilibrium point in the overall rankings, where due to his lack of steals and home runs, the best he can reasonably hope for is to "tread water" by keeping his batting average on its current lofty perch.

Remember, in the end, Momentum is only relative and only from this point forward. Just because Cabrera has a negative momentum (-12) doesn't mean he won't finish the season at the top of the ESPN Player Rater. However, we can simultaneously believe he can achieve that and that he is more likely to be the 15th overall player from this point forward than the second. It's just that many of the players who will beat out Cabrera over the next two months are currently far, far down the overall statistical mountain.


Note: AJ Mass' top 100 hitters are ranked for their expected performance from this point forward, not for statistics that have already been accrued.

Four up

Alex Gordon, Kansas City Royals: Gordon is up because, well, he's up. Back to Kansas City after working on shortening his swing at Triple-A, he had a seven-game hitting streak and two home runs. It's clear that playing the outfield as opposed to manning the hot corner is treating the former "next George Brett" well. Perhaps he'll be the "next Amos Otis" instead; that wouldn't be so horrible, would it?

Jorge Cantu, Texas Rangers: Cantu has 54 RBIs on the season, with only 28 percent of his at-bats with the Florida Marlins coming with runners in scoring position. Compare that with the 40 percent of at-bats with which Justin Smoak had the similar opportunity to drive in some runs and failed to do so more often than not. Cantu can simply perform exactly the same as he did with the Marlins and expect to see a huge increase in run production, just because his lineup in Texas is far superior.

Jose Bautista, Toronto Blue Jays: Bautista survived the trade deadline intact, which is great news for his owners, as he thrives at the Rogers Centre: 20 homers at home versus 12 on the road and a .295 batting average in Canada versus .232 in the United States. He's got 29 home games left on the schedule. Sit back and enjoy the ride.

Alfonso Soriano, Chicago Cubs: He just needs a little help from his friends -- yes, we're looking at you, Aramis Ramirez and Marlon Byrd. When Soriano leads off an inning, he is hitting just .161 this season. But for whatever reason, be it because he focuses better or simply takes advantage of a different style of pitching when men are on base, you can't complain at all with his .293 batting average in those at-bats. As long as he gets some support, his value should continue to be on the upswing.

Four down

Ryan Howard, Philadelphia Phillies: Other players have suffered drops as a result of injuries as well, like Carlos Santana and Justin Morneau, and missing two weeks at this point of the season -- something that is looking likely for Howard as he left the team to visit team doctors back in Philadelphia -- simply has to cause your ranking to plummet. With as much bad luck as the Phillies have had in terms of injuries this season, fans can only hope Howard isn't sidelined for any longer than a short DL stint.

Curtis Granderson, New York Yankees: Lance Berkman now wears pinstripes and plays every day as the designated hitter, but the trade that means the most to Granderson is the acquisition of Austin Kearns. With the new arrival batting .261 against left-handed starters compared to Granderson's .220, expect Granderson's playing time to dip, though as a small consolation prize, his batting average should go up.

Chone Figgins, Seattle Mariners: How can I call Figgins an underachiever and yet still drop him eight spots in the rankings? He's definitely starting to come around, having hit .360 in his past six games (through Aug. 1), but I think expecting him to rise as high as 72 overall is asking a little bit too much, especially when you're dealing with essentially a two-category handicap.

Pablo Sandoval, San Francisco Giants: Since June 23, the Kung Fu Panda has had 139 plate appearances and no home runs. It's not just a matter of bad luck. Sandoval is simply not making contact lately, as his K/BB rate has risen to 2.18 over this stretch as opposed to 1.36 before it started. There's something not right here, and we're not about to wait around for him to figure it out.

Upgrade your roster

Add: Ian Desmond, Washington Nationals
Drop: Cliff Pennington, Oakland Athletics

With Cristian Guzman shipped off to Texas, the everyday shortstop job in Washington goes to Ian Desmond, no questions asked. Without having to look over his shoulder anymore, he's hit .314 over the past two weeks with eight RBIs. He still needs to be a little more patient at the plate in order to improve his on-base percentage -- currently a lowly.295 -- but that's also a function of batting eighth in a National League lineup. After all, why take a walk only to have your pitcher strike out on three flails?

Meanwhile, those three April home runs are drifting further and further into the rearview mirror for Pennington. Twice in the past week, Adam Rosales -- hitting .333 since July 1 -- has started in his stead at shortstop. Pennington's glove skills are not in question, but the A's need to score runs, and in that department, the only one that really counts for fantasy, there's not a lot to see here. It's time to jump off this Cliff.

Also consider adding …

Danny Valencia, Minnesota Twins: Owned in only 6 percent of ESPN leagues, the rookie third baseman is hitting .500 over his last nine games, all complete game affairs, for the Twins. With Nick Punto on the disabled list, as long as the kid keeps hitting, he'll stay in the lineup.

Jon Jay, St. Louis Cardinals: His performance at the plate allowed the Cardinals to ship Ryan Ludwick to San Diego. That's quite the vote of confidence, given the small sample size, but with Albert Pujols hitting behind him, he's sure to see a whole lot of quality pitches to hit.

Chris Snyder, Pittsburgh Pirates: The move to Pittsburgh finally gets Snyder out of Miguel Montero's shadow, and with Ryan Doumit's ability to be moved to other positions, the Pirates' new backstop should be able to rediscover a rhythm with the bat. Expect Snyder's batting average to increase by a good 30 points with regular work.

New position qualifiers

Twenty games: Mark Kotsay (1B) and Ramiro Pena (SS)
Ten games: Emilio Bonifacio (OF), Placido Polanco (2B) and Pablo Sandoval (1B).
Five games: Jamey Carroll (OF), Brent Lillibridge (2B), Mark Reynolds (1B), Scott Sizemore (3B) and Matt Tuiasosopo (3B).
One game: Mike Aviles (3B), Jeff Baker (1B), Chris Gimenez (OF), Mike Hessman (3B), George Kottaras (OF), Mitch Moreland (OF), Donnie Murphy (3B), Marcus Thames (3B) and Luis Valbuena (3B).

AJ Mass is a fantasy baseball, football and college basketball analyst for ESPN.com. You can follow AJ on Twitter or e-mail him here.