One of my favorite Bill James essays was one he wrote in the 1983 Baseball Abstract about the use of statistics at the halfway point of the season to determine which players should be chosen for the All-Star Game.
Toby Harrah, a mediocre third baseman, had a set of statistics in the first half of the 1982 season that were somewhat better than those of perennial All-Star George Brett. But Brett received the nomination over Harrah, and there was some hue and cry among fans and the media about this.
James explained in typically clear Jamesian detail how Harrah's .336 batting average and 17 home runs at the All-Star break obviously were not indicative of his true performance level. The fans recognized this, and Harrah's season-ending total of 25 homers and a .306 average proved them and James correct.
This same sort of thing happens in the NFL. It causes players who are having solid campaigns from Weeks 1 through 9 to become overrated. That is the case for most of the following five players, all but one of whom are riding somewhat misleading statistical waves to Pro Bowl contention.
Cutler's 16 touchdown passes rank third in the league, and his 2,169 passing yards are fourth-best. He also is a favorite among fantasy players, as his 128 points currently rank him sixth in overall scoring in ESPN leagues.
As impressive as those cumulative figures are, Cutler's performance level has declined dramatically as the season has progressed. Cutler had a passer rating of 93 or higher in his first three games but has topped that mark only once since then. That drop-off has lowered his passer-rating ranking to 16th.
Another reason Cutler makes this list is that he hasn't improved in the one problem area that plagued him during his first two years: bad-decision percentage. It is quite difficult for any team to be successful when its quarterback has a bad-decision rate of 4.0 or higher, and Cutler was at or over the 5.0 mark in his rookie and sophomore professional seasons.
He hasn't shown any progress on this front in 2008, as his 5.3 mark in this metric indicates. Unless and until Cutler can push his mistakes total down to an acceptable level, he'll never be the great quarterback he's capable of becoming.
It is hard to knock any defensive lineman who puts up 10 sacks in eight games, but let's take a closer look at Abraham's sacks.
In Week 1, he posted a one-on-one sack against Detroit right tackle George Foster. Only six tackles gave up more sacks than Foster in 2007, and Foster started only nine games that year. He's obviously a below-average pass-blocker, so beating him isn't an indicator of great pass-rush skill.
That is the case with all four of Abraham's one-on-one sacks. He beat the Chiefs' Damion McIntosh for a sack in Week 3 and destroyed Oakland's Kwame Harris for two sacks in Week 9. McIntosh has bounced around the league throughout his career, and Harris is so bad that he probably shouldn't even be employed in the NFL.
If that wasn't enough to bring Abraham's sacks explosion into perspective, consider that four of his sacks are coverage sacks and one is a run sack. All of this doesn't mean that Abraham is having a bad season, but multiple pass-rushers are having better seasons than he is, and they deserve the Honolulu trip more than Abraham does.
Mayo is a perfect example of a player whose tackles total raises his perceived performance level well above what it truly is. Mayo won the rookie defensive player of the month award in October largely because of his 24 tackles in that period.
Mayo's point-of-attack (POA) run metrics for the season show that he actually is struggling quite badly in one of the primary functions for his position. I have broken down six of the Patriots' eight games, and in that sample, Mayo has been at the run POA 34 times. He has defeated only six of those blocks, which equates to a POA win percentage of 17.7. If historical trends are a good indicator, that would place him in the bottom quarter of the league at season's end. His run-stuffing prowess is probably even worse than that if the 7.2 yards per attempt on the POA runs is added to the analysis.
I didn't want to put two players from one team on this list, but Marshall is ranked fourth in receptions and eighth in receiving yards. That type of showing all but assures he will receive much Pro Bowl consideration, so it makes him worth a closer look.
The extra examination time doesn't do him much good. Marshall is averaging only 7.1 YPA, which not only is below Pro Bowl-caliber, it also could place him in the lower half of the league in that metric at season's end. Marshall also is averaging only 7.0 YPA when facing someone in coverage, be it a cornerback, safety or linebacker. That doesn't compare favorably with his 7.4 YPA against cornerbacks in 2007 and is a sign that Marshall has regressed some in 2008.
It was a bit difficult to name any cornerback as overrated because the main criterion most people use to decide who to pick for the Pro Bowl at this position is interceptions, and no one has a significant lead there. But Barber is a big-name cornerback on a team that's making a resurgence, and he has a high-profile twin brother who can pitch him to a national television audience every week. That means he has a lot of advantages in the hype tiebreakers.
Where he doesn't have an advantage is in the metrics. I have graded seven of the Buccaneers' eight games, and Barber has an 11.2 YPA and a 24.1 percent success rate. Both of those are the types of statistics that would get a young player benched or cut, but Barber has the career clout that allows him to weather this type of subpar-performance storm. Just because he keeps his job, however, doesn't mean he is worthy of the postseason honor roll.
KC Joyner, aka the Football Scientist, is a regular contributor to ESPN Insider. His core coverage metrics for all skill-position players and cornerbacks are available in the ESPN Fantasy Football Magazine. His new book "Blindsided: Why The Left Tackle is Overrated and Other Contrarian Football Thoughts," is available in bookstores and on Amazon.com. For more information, check out KC's Web site, www.thefootballscientist.com.