I don't get it.

And I don't buy it.

I don't get why John Street refuses to say whether he'll reappoint John Timoney as police commissioner if Street wins the mayor's race in November.

And I don't buy the explanation that doing so would invite speculation about other potential appointees that would divert attention from the campaign.

"It becomes a distraction, and you're trying to focus on a campaign," Roy Jones, Street's press spokesman, said yesterday.

Then how come Street's opponent isn't having that problem?

GOP mayoral candidate Sam Katz has announced his intention to keep Timoney - and his campaign isn't crippled by a clamor for other appointments.

"Occasionally, if we're before a group that has a particular issue, they'll ask us about a particular person - but that's because they're a special-interest group," said Bob Barnett, Katz's campaign manager.

But there's been no distracting pressure to name other key appointments. And if there were, Katz would easily dispel it by announcing that Timoney's "been doing an outstanding job and I want him. I'm not going to sit here and evaluate other people," Barnett said.

Nothing, with the possible exception of education, is more important to city residents than crime. And voters like John Timoney.

"They see him, he's visible, he's a commissioner who's out at everything from charity events to neighborhood festivals to substantive anti-crime kind of meetings," Barnett said.

"The public seems very happy with him as well as with the results - and a big part of results in crime-fighting is often feeling better about your neighborhood. He gives them that as well as. . .things that are substantively fighting crime better."

Barnett also praised Timoney's glad-handing charm - but could that be what's giving Street pause?

"Timoney does all the things that not only a good police chief would do, but a good politician would do - it's very much in that Rendell style of going out and being with people," Barnett said.

Could Street be afraid that his own stern demeanor would contrast unfavorably with that of his police commissioner? Is Timoney's popularity simply too threatening?

Some leaders, that argument goes, surround themselves with weak subordinates to prevent a challenge to their power and to avoid being outshone.

New York Mayor Rudy Giuliani, after all, ousted noted Police Commissioner William Bratton - Timoney's mentor - when Bratton won too much acclaim for crime-fighting there.

But Timoney isn't a scene-stealer like Bratton. And Street is surely more secure than that.

Or, given Street's reputation as a fierce power player, is he avoiding the automatic reappointment of Timoney because he wants to extract something in return - whether it's jobs or control?

There's even talk that Street feels compelled to appoint an African-American police commissioner - despite the fact that he helped engineer the ouster of former Police Commissioner Richard Neal and helped recruit Timoney here.

Given the critical nature of the police commissioner's job, I doubt that many city residents would choose a racial appointment over a proven commodity.

Timoney's methods in Philadelphia haven't invited the same accusations of police brutality and civil-rights violations as in New York. And while there may be another potential commissioner who's black and as good as Timoney, why risk removing someone who's doing such a great job?

But speculation about Street's motives, groundless and unflattering as it might be, persists because the reappointment of Timoney seems like such a no-brainer.

And speaking of risks, what about the possibility that Timoney might get an attractive job offer - one that's firmer than current speculation about his being appointed police commissioner by the next mayor of New York City?  With his future here in doubt, why wouldn't Timoney take the right job if it came along?

And then Street would be like the proverbial fisherman lamenting the big one that got away.

And if he lets Timoney get away, something else might get away from John Street, too.

Like the room with the big desk on the second floor of City Hall.