Re: John Dewan - Defense worth 50% of offense
Leave it to the guy that makes his living selling defensive metrics to overstate the importance of defensive metrics.
It is no surprise that exaggerating the number of runs saved/lost by fielding will inflate the ratio of fielding to offense.
Asking John Dewan to place a value on defensive metrics is like asking the owner of Jiffy Lube how often you should have your oil changed.
How many copies of the Fielding Bible would he sell if he estimated that fielding didn't have much impact on run scoring? It is in his financial best interest to advertise the importance of fielding.
If you want a fair appraisal you should rely on a neutral appraiser rather than trust someone with a vested interest in the outcome.