Count Keith Olbermann among the otherwise well-informed New Yorkers who don’t have a clue when it comes to what’s happening with the MTA.

Giving transit chief Jay Walder the "Worst Person in the World" treatment last night, the "Countdown" host rattled off a list of service cuts and other measures approved yesterday before concluding as follows:

"All this is the result of the shocking, total surprise budget shortfall that the MTA has had every 18 months or so for about the last four decades. The latest: $400 million they suddenly discovered last week they just didn’t have. I know this is a local thing but this has been going on since I was a kid. It is the biggest running scam in this town since they caught Boss Tweed."

Olbermann or his producers must be aware that Walder is new to his MTA post, as he is offhandedly referred to as "this month’s chairman." Which makes it even more surprising how widely this misses the mark. It’s not clear what exactly he means by "biggest running scam in this town," but since Olbermann singled out Jay Walder for a public flogging — and not Sheldon Silver, Carl Kruger, Pedro Espada, Richard Brodsky, or any of the myriad electeds who have continually shortchanged transit for, yes, decades — it’s obvious that he buys into the fiction that every MTA crisis is of its own making.

Here’s the reality of the latest "total surprise budget shortfall":

• The state legislature took $143 million from the MTA to plug its own budget hole.
• The funding solution that Albany promised would maintain service didn’t deliver the revenue that the state projected.
• New York State cut funding to help get kids to school by nearly 90 percent. We’re pretty much the only place in America where local government doesn’t cover that.

To paraphrase Don Imus: Keith, we like you. But please do your fellow New Yorkers a favor. Read up, then train your ire on those who actually deserve it.