On page S-33, Mitchell makes the following statement:

I urge the Commissioner to forego imposing discipline on players for past violations of baseball's rules on performance enhancing substances, including the players named in this report, except in those cases where he determines that the conduct is so serious that discipline is necessary to maintain the integrity of the game. I make this recommendation fully aware that there are valid arguments both for and against it; but I believe that those in favor are compelling.

If Mitchell had gone into the investigation with this in place and assurances from the government that players would not be prosecuted, he might have received more cooperation from players. I wrote about this during the summer for Baseball Prospectus (subscription required).

There exist many benefits to such a truth commission. Ending the constant speculation surrounding players would be a welcome relief. Instead, we can start looking at their records to debate what the drugs meant for their careers. Voters for the Hall of Fame could finally decide the worthiness of a candidate without guessing about steroid use. And we can finally gauge how fans really feel about the use of these substances. Do they boo and shun, or forgive and forget?

The other benefit is one to help police the sport in the future. Knowing when players started using drugs and the type of drugs used allows sabermetricians to study the change in performance associated with their use. It might be possible to build a probabilistic model to estimate the chance that a change in production was due to performance enhancing drugs. Knowing patterns of procurement and use might allow baseball to look for behaviors that indicate abuse.

Yes, players' reputations will suffer. Fans forgive, however, as they've done with Jason Giambi. But the players need to come clean and show contrition. George Mitchell needs to use his gravitas with both MLB and Congress to bring about the conditions required for honest testimony. Perhaps with that, the "steroid era" can finally pass into history. Without a truth commission, the investigation is destined to be stymied by a lack of player cooperation.

Instead we received a report full of hearsay. Clemens and Pettitte come out looking poorly, but players like Brian Roberts are tarred without a lot of evidence.