From BR Bullpen
Black Ink or the Black Ink Test is a measure of how often a player has led the league in "important" statistical categories. It is named as such because league leading numbers are traditionally represented with Boldface type and was first used in Bill James's The Politics of Glory. It may serve as a tool to evaluate how a player compares to Hall of Famers, as the average batting score is around 27 and pitching score is around 40.
Players from different eras can usually not be directly compared by means of the test, because it is harder to lead a league with 16 teams than it is to lead a league with 12 teams or 10 teams or 8 teams.
 Points System
 Batting Statistics
- Four: home runs, runs batted in, or batting average
- Three: runs scored, hits, or slugging percentage
- Two: doubles, walks, or stolen bases
- One: games, at bats, or triples
 Pitching Statistics
- Four: wins, earned run average, or strikeouts
- Three: innings pitched, win-loss percentage, or saves
- Two: complete games, walks per 9 innings, or hits per 9 innings
- One: appearances, starts, or shutouts