The Hardball Times Chris Jaffe has a pretty interesting take on the 2008 postseason debacle. One of his assertions is that the relationship between the moves Lou made in the 2007 post season and then the preparation for the 2008 post season after the division was clinched, had a significant impact on the self confidence of the team going into October.
It's unduly simplistic to claim a sole cause for the 2007-8 shortcomings, but some underlying causes can be rooted out. A key one revolves around the decisions and actions of the team's manager, Lou Piniella.
...for two straight years Piniella has prioritized physical preparation for his team. Both times the playoffs made painfully obvious that the Cubs sorely needed better mental preparation. What's more, his decision to prioritize physical preparation has likely helped cause their mental shortcomings.
The decision to treat players differently because the postseason is coming up sends the team some signals. First, it loudly pronounces to the players that the upcoming games are fundamentally different from everything they've experienced before. Second, it implies that they can't be trusted to win unless they approach this somehow differently.
If you think the team can just keep playing as they have all year and win, there's no need for any fancy adjusts on the verge of the postseason. Instead, these notions can make a team self-conscious. That's the single worst thing that can happen to a team. If you have to think about what you're doing, it won't be done properly. It should come naturally.
At the end of the day we all know the players didn't execute. Its been easy to point the finger at Soriano, Ramirez and Dempster, but perhaps Lou's post season preparation and plans had a far greater impact on that execution than any of us have been willing to admit.