Do you know where the YQL player IDs come from? Considering that has a direct data feed for scorecards that might be the easiest one to implement.Matt, I can set up a google spreadsheet so that everyone can collaborate on that.
Regarding the cricinfo ID, I had looked at their scorecards earlier, and there doesn't seem to be any links with the IDs in the scorecards. A quick search later, I found cricbuzz.com using the IDs in their scorecards, and also, they were in a nice tabular form, which may make it easier for us to extract the scores automatically.
I'm not attached to a particular provider, just as long as it'd be flexible enough into the future.