The NPB has released a document the Salary Arbitration Committee's prepared. I have provided a quick translation of the more important aspects of the document down below:
There were four meetings.
The Lions said they would pay 220M yen plus 20M yen in incentives. They went as high as 30M yen in incentives, but no high than that.
Hideaki Wakui wanted 300M yen at first, then dropped his demands down to 270M yen, then 250M yen plus 20M yen in incentives. But an agreement could not be reached.
Seibu claimed that based on their assessment, Wakui was supposed to get a pay cut, but because of his 14 wins, the club decided they would pay him the same amount he made last season. They also said that his year-end performance also weighed heavily in their decision and that they didn't think looking into salaries for other pitchers on other teams made much sense.
Wakui felt the Lions should look at both his stats from last season and his stats over the last few years. He also felt it wasn't fair that the Lions weren't looking at this stats from last year as a whole, but rather focusing on his year-end numbers. Wakui pointed out that position players were looked upon favorably, in comparison to pitchers and that the club's offer was too low. He wanted 270M yen at the very least.
The committee bases their decision on what they feel a player is capable of doing this year, based on how well he did last year. They also look at other things like: stats from the year before last, the team's record from last year, titles the player may have won, popularity of the players, expectations of the player, how the player stacks up against past and current players, and the club's current financial standing.
Regarding comparing a player against players from other teams... The committee felt that you cannot just simply throw this out because it doesn't make sense. The fact is, what other players do and how they are treated can tie directly into a players motivation, as well as improve a team's image.
The committee listed the following reasons for giving Wakui a pay raise and a pay cut:
Wakui had a good record as the team ace and a good ERA as well
Wakui has played 6 years in the pros and in the last 5 he has not left the starting rotation and has consistently won 10+ games a year.
Based on his past performance and stability, it would be safe to expect him to post similar numbers in 2011.
He is considered one of the top pitchers in the league and as such the club needs to consider the motivation of the player.
His 2010 stats did see a drop from his 2009 stats.
He didn't perform well down the stretch, especially in games that were on the line, which means he didn't meet expectations as the team's ace.
The committee considered all these points and ultimately decided that Wakui deserved a 15% raise (253M yen).
Note: this was the first case handled under the new salary arbitration committee rules. The committee itself used to be made up of the NPB commissioner and the two heads of the leagues. But with the merging of the two offices, a new system had to be developed. The player's association pushed for more balance in the system and so the committee is made up of 2 lawyers and 1 former player.