10 best Buffalo Bills players of all-time (by Approximate Value metric)

The analytics movement in football is still in its infancy, but there are plenty of statisticians out there trying to come up with the next big number that brainy front office execs can use while building their rosters.

Pro Football Reference has an interesting stat called approximate value (AV for short). You can find a (very detailed) explanation of the metric here, but essentially, it's a football version of Bill James' 'win shares' statistic. A point total is determined for each unit (offense and defense) in a given season, and those points are divided among the players based on their individual performances. Players are limited by the total points their unit earns, but better players earn a greater share of the points. It's not a perfect statistic, but it does help to differentiate great from good, and good from average.

Here, according to the AV metric, are the ten best players in Buffalo Bills franchise history.

10. Jim Ritcher, OG (AV: 88)

Ritcher was a strong player on some pretty weak teams in the mid-'80s, paving the way for Joe Cribbs and Greg Bell during those lean years. He held on to a major role into the latter stage of his career, starting at least 10 games during each of the team's four Super Bowl seasons. His AV peaked at 14 in 1991, and remained at 11 the following season; both years ended with a Pro Bowl appearance.

9. Mike Stratton, LB (AV: 95)

Stratton came to the Bills in 1962 with little fanfare or expectation. He left a decade later as, arguably, the most well-rounded defender the Bills have ever fielded. His legendary "Hit Heard 'Round the World" on Keith Lincoln in the 1964 AFL Championship Game was the highlight of his career, he was an AFL All-Star every year from 1963 to 1968, and he was voted to the all-time All-AFL second team after the league's conclusion in 1970. Five of his All-Star seasons saw his approximate value rise above 10, with a high of 14 in 1964.

8. Fred Smerlas, DT (AV: 97)

Behind one of the best mustaches to ever grace an NFL field was the pre-eminent Bills defender of the early 1980s. Smerlas went to four Pro Bowls in that stretch, and even made first team All-Pro in the strike-shortened 1982 season, when he recorded his career-high AV of 17. He became slightly less prominent after a certain Hall of Fame pass rusher showed up, but still managed to snag one more Pro Bowl nod in 1988.

7. Joe Ferguson, QB (AV: 100)

Ferguson never made an All-Pro team, nor was he ever voted to a Pro Bowl (although his 1975 season, when he led the league in touchdown passes and recorded his career-high AV of 14, was an oversight by the voters). He finished among league leaders for interceptions thrown six times in his 12 Bills seasons, leading the league twice, and recorded a losing record over 163 starts. His teams never finished above .500 without a 1,000-yard rusher. Still, he stuck around for a long time, and was able to make plays with his arm when he needed to. Ferguson was a good complement to a run-first offense, and the kind of quarterback the Bills would kill for in 2015.

5(t). O.J. Simpson, RB (AV: 107)

It's slightly surprising to see Simpson so low on this list, but in reality, he only had five really strong seasons. Of course, among those five seasons were the first 2,000-yard rushing effort in NFL history (still the record for a 14-game stretch), and a Herculean effort in 1975 that gave him the second-highest single-season AV in NFL history (25). Other than that five-year stretch, he put up some pedestrian numbers, including his final seasons in San Francisco.

5(t). Kent Hull, C (AV: 107)

Hull came to the Bills from the USFL with a much higher-profile teammate, and remained relatively anonymous in the trenches while the other guy (and his popular running mates) basked in glory. He was only voted to three Pro Bowls and named first team All-Pro twice in his 11 seasons, but he played a major role in allowing the K-Gun to operate as the leader of one of the better offensive lines of the era. The AV stat doesn't give much help to centers, but Hull still managed to reach 12 or higher four times, including a high of 16 in both 1990 and 1991.

3(t). Andre Reed, WR (AV: 132)

The greatest receiver in Bills history and a 2014 Hall of Fame inductee, Reed was a very good wideout for a very long time. He never led the NFL in any major receiving category, which will happen when your career parallels Jerry Rice's, but he did make seven Pro Bowls and reached double-digit AV six times, with highs of 14 in 1989 and 1994. His team records of 941 receptions, 86 receiving touchdowns, and 13,095 receiving yards are not going to be broken for a good, long while.

3(t). Jim Kelly, QB (AV: 132)

The fact that Kelly could equal Reed's career AV total while spending four fewer seasons with the Bills speaks to why he was a first-ballot Hall inductee in 2002. He reached double-digit AV nine times, topping out (like many Bills of the era) in 1991 with an AV of 17. That was the year of his only first team All-Pro nod, although he did make five Pro Bowls. Kelly is easily one of the best football players of his generation, and the best quarterback the Bills have ever had by a significant margin.

2. Thurman Thomas, RB (AV: 138)

Slightly above Kelly and Reed is the third triplet, who made five Pro Bowls and earned two first team All-Pro nominations, and also tacked on a league MVP award in 1991. He only recorded a double-digit AV six times, but peaked with an absurdly high 20 in 1990 and 1991. He never led the NFL in rushing, but did lead the league in yards from scrimmage four times, making him possibly the best all-around back of an era that included Emmitt Smith and Barry Sanders. He joined Kelly in Canton in 2007, his second try at the Hall.

1. Bruce Smith, DE (AV: 194)

It's amazing to see how far ahead of the pack Smith is, but at the same time, it's not very surprising. Approximate value requires players to share points, so while the last few guys had to split the pool among themselves, Smith was largely in a class of his own. He had plenty of good teammates, but Smith was always on another level, which is why he's the NFL's all-time sack leader with 200. He recorded a double-digit AV an astonishing 12 times, topping out at 21 in 1996 (as a 33-year-old, when he won his second Defensive Player of the Year award). He even tacked on 29 AV points in Washington, giving him the seventh-highest AV total in NFL history.