Explanation of ERAs for ODI batsmen and bowlers

ODI Earned Run Averages:

ERA is a statistic borrowed from baseball which is especially
useful for comparing limited overs players. The baseball ERA is
the amount of runs a pitcher would give up were he to pitch an
entire game.  The cricket ERA is just the same, and it can be
calculated for batters too.

It meets Bill James'(*) 3 criteria for a good sports statistic
     1) It is easy to calculate
     2) The result is easy to understand and fits in a logical 
        context
     3) It provides information we can't get elsewhere

1:  ERA = MIN(10 * runs/wicket OR 55 * runs/over)

      Substitute the # of overs in a match for 55 if less than
      55 are played in the league you are calculating the stats
      for.  Wides and no-balls should be counted against the
      bowlers, but not for the batters.

2:  The ERA is the number of runs a player would give up or
    score were he to play the entire game, so it can be compared
    to ODI team totals:  300 is bad for a bowler, 100 is good.
    Much easier than trying to decide what a good per-wicket
    average should be.

3:  The ERA lets you compare strike bowlers with economical
    bowlers, allowing each to be in his best environment.
    Per-wicket averages are unfair to economical bowlers, while
    per-over is unfair to the strike bowlers.

    Batting and bowling effectiveness are put on the same scale,
    so all- rounders can be compared and one can determine
    whether a batter or bowler is the most valuable player.

ERA analysis says that teams should choose an attack of either
strike or economical bowlers, but not mix them.  If they are
mixed, neither will be used to full advantage.  Of course in the
real world, you need at least one bowler who can dislodge an
entrenched partnership before they do serious damage.  And for
batting, a team s best mixing players who score quickly and
players who build good averages, so they neither use up overs
nor wickets.

(*)Bill James: the Bill Frindall of baseball!  See his "Baseball
Abstract" series, and "The Great American Baseball Stat Book"

 Contributed by Matthew.Mitchell (mmitchel@libertynet.org)