Beware of big names. Amid the jittering and convulsive jubilation on Oilers web boards, one wonders if they're rejoicing for the Mike Peca of 2001, and not the Mike Peca who hasn't fully recovered from a devastating knee injury.
For me, York was the Oilers best player in the last two seasons. Brewer was functionally more important, but I valued York's consistency and all-round game. For pro-trade people, the party line is that while York had better offensive numbers, Peca is a better defensive player, which is why he was relegated to a third line checking role.
Of course defence is harder to really gauge on the ol' plus/minus, which is why I thought of SI's ill-named and now defunct Statitudes website, which had a interesting article on a using pythagorean formulas to determine an individual's contribution in a team's win shares. Basically it's using the same principles behind Bill James' Sabrmetrics in baseball, number crunching towards a better, more accurate way of measuring a player's performance. To do this you start with goals for and goals against, which are the foundation of a team's winning percentage, and from that you can determine the marginal goals (created and prevented) which contributed to that differential (including how many of those goals it took on average to win game), and from that you can determine an individual's contribution. Luckily I found a bunch of research for the 2003 season and the results have a few bits to chew on:
Mike Peca's Player Contribution for overall defence is 18.
Mike York's Player Contribution for overall defence is 23.
The general range for players was 1-50, which basically means both were pretty much the same defensively. However, Mike York's overall player contribution, including offence, is 54 compared to Peca's 41. The goals and assists don't lie, and I don't think a closer look bears out the idea that Peca offers more defensive upside.
Side Note: Aside from goalies, Chris Pronger had one of the highest Player Contribution share (range 1-120) in the league: 105. Eric Brewer had a score of 64. It also might be worth noting that Tommy Salo had a overall PC of -26, which means he didn't belong in the league and was actually hurting his team (we all knew this anyway, didn't we?).
Of course you can't measure leadership and other such intangibles, but I find that to be overrated anyway. Messier supposedly is a "great leader" but that hasn't helped his teams make the playoffs in a decade. Just like in life, being a great leader is a combination of being likable and respected, which is mostly from showing up and do your job well. Peca has a much higher profile than York, but I don't think that is going to make the team better next year. Peca's knee injury and pricetag only make the deal worse.
Peca - Salary = 3.99 --- Games = 222 --- PPG = 0.64 --- 5'11" / 190 lbs --- Age = 31
2003-04 ... 76 gms ... 11g 29a = 40 pts ... +17 ... 71 pms ... 19 mins/game ... 0 PP .. 1 SH
2002-03 ... 66 gms ... 13g 29a = 42 pts ... -04 ... 43 pms ... 19 mins/game ... 4 PP .. 2 SH
2001-02 ... 80 gms ... 25g 35a = 60 pts ... +19 ... 62 pms ... 20 mins/game ... 3 PP .. 6 SH
York - Salary ~ 2.00 --- Games = 213 --- PPG = 0.72 --- 5'10" / 185 lbs --- Age = 27
2003-04 ... 61 gms ... 16g 26a = 42 pts ... +18 ... 15 pms ... 19 mins/game ... 1 PP .. 2 SH
2002-03 ... 71 gms ... 22g 29a = 51 pts ... -08 ... 10 pms ... 19 mins/game ... 7 PP .. 2 SH
2001-02 ... 81 gms ... 20g 41a = 61 pts ... +07 ... 16 pms ... 20 mins/ game ... 3 PP .. 0 SH