What about total WAR accumulated by rookies? Would be curious to see if the “volume” of wins created by rookies increased. Or perhaps Rookie WAR as a % of total league WAR by year. That would be awesome.
This sounds like something I could try, but we’d probably have to make it total rookie WAR divided by number of teams in the league, right? That way we could see if the average rookie WAR by team is going up.
You’ve graphed the number of debuts and the productivity, but you didn’t graph reliance on the rookies. I’d be interesting to see a graph of GS by Rookies (or whatever playing time measuring stick).
Honestly, I think the Year of the Rookie was actually the “Year of the Baseball America Top-10 Organizational Ranking Rookie.”
Seems like a lot more of the big names got the call, regardless of age. Wouldn’t be surprised if the average age — which must correlate with hype — went down if it’s limited to.. whatever amount of dudes. Wouldn’t be surprised if the minor league playing time before a debut also went down. Peeps are also following minor league ball and prospects a lot closer because of the interwebz as well.
“Usually a debut is precipitated by an injury or poor performance by the veteran who used to own that role”. I’d have liked to have seen that answered. Are veteran players spending more time on the DL, leading to the need for more debuts?
You also offer, “This general upward trend in the use of rookies seems to suggest that teams have realized that getting the most out of their cost-controlled players is sound baseball economics.” It would be interesting to know if the increased debuts is driven by decreased performance of veterans or a more intentional shift toward more affordable players.
Incidentally, these two possible causes could be related. As teams are becoming more value-driven in their decision making, they may be becoming more cautious with injuries to their valuable assets. Instead of letting a veteran play through an injury, maybe they’re letting him sit a bit longer and giving a kid a shot in his place. Just a thought.
Good point. Though perhaps using just as a percent of total league WAR would get around it as well. Either way, normalization is sweet. Will look for it, and try not to cry too much if it doesn’t happen.
Would be cool to be able to say that “Rookies contributed 20% more Wins in 2010 than 2009”. But you know, with like the real number. Gets at reliance on rookies which is an interesting idea that freefantasy brings up below.