Mayor Bloomberg has played the most exclusive golf courses in the country, made regular appearances at charity golf outings, and has the money for all the lessons he could ever need. So, how good is his game?

By most accounts, he is a decent but very determined golfer.

The world’s no. 3-ranked professional golfer, Phil Mickelson, who played 18 holes with Mr. Bloomberg early yesterday during a charity event at Westchester Country Club, tipped his hat to the mayor’s game.

“I was actually impressed,” Mr. Mickelson told ASAP Sports when asked for an analysis of Mr. Bloomberg’s game after their round. “I thought that he came in as a 21 handicap and he must have had four or five natural pars, which helped the team immensely.”

When asked about the mayor’s handicap, his spokesman, Stuart Loeser, joked: “Most days, I am his handicap.”

Mr. Mickelson said the mayor net birdied, a term used to factor in the player’s handicap, the first two holes. For the round, his foursome scored a two under par 69. A breakdown of individual scores was not available, and the mayor’s office declined to release his.

While Mr. Bloomberg hasn’t posted any of his scores with the Metropolitan Golf Association since shortly after coming into office in 2002, most accounts suggest his handicap is somewhere between 18.1 and 21, and some of his golf partners say he’s been improving on the links.

Mr. Bloomberg has not been shy about his passion for golf. He sometimes mentions his golf games at public appearances and has been known to play regularly at private clubs in Westchester, Long Island, Bermuda, and Florida, as well as at public courses in the five boroughs. In 2002, the New York Post reported that he jetted the state’s top two legislative leaders to his mansion in Bermuda to take them to golfing and talk about looming budget problems.

A golfer who caddied for Mr. Bloomberg at McArthur Golf Club in Hobe Sound, Fla., Brian Anderson, told a newspaper in Illinois that the mayor was an “unbelievable guy.”

“I’d say he’s an 18 to 20 handicap, but he loves golf,” Mr. Anderson was quoted as saying in March. “He’s the most determined person I’ve ever seen.”

The State Journal-Register in Springfield, Ill., quoted Mr. Anderson’s father as saying that Mr. Bloomberg is helping to pay for his son’s professional golfing aspirations under the condition that 10% of any winnings get donated to charity.

Mr. Anderson was quoted as saying that the mayor flew into the club via helicopter and played 36 holes, while two bodyguards followed along in a cart. When reached by telephone yesterday, Mr. Anderson declined to comment, saying McArthur Golf Club has rules against discussing members.

Mr. Bloomberg reportedly took up the game some time around 2001, and in June a Bloomberg supporter, investment banker Steven Rattner, told the New York Times the mayor “picked up golf, and now he’s determined to catch Tiger Woods.”

That seems consistent with his approach to his government and business dealings. In business, he turned an idea to deliver financial information into a multibillion-dollar company. In government, he came into City Hall having never held public office and is now regularly grilled about whether he wants to be president.

The district attorney of Staten Island, Daniel Donovan has made a tradition out of golfing with Mr. Bloomberg after the July 4th parade on Staten Island’s South Shore.

“I’ve seen great improvements in his game,” Mr. Donovan said yesterday. “My recollection when we first started playing six years ago was that he was an okay golfer, and I think he’s become a very good golfer.”

Unlike President Clinton, who has a reputation for taking Mulligans, as do-overs are called, the mayor sticks to the rules.

“He’s strictly by the book … and there are very few people you can say that about,” Mr. Donovan said. He also said the Mr. Bloomberg’s companion, Diana Taylor, who is often with him on the course, is a strong golfer.

Mr. Bloomberg is one of an array of politicians to make a passion out of golf. While he has said he does not want to run for the White House, if he changes his mind, he’ll have a common thread with a line of past presidents.

The topic was even the subject of the 2004 book “First Off the Tee: Presidential Hackers, Duffers, and Cheaters, from Taft to Bush,” by Don Van Natta Jr. Presidents Nixon and Eisenhower each reportedly had holes in one. President Ford had a handicap in the mid-teens until age 80. President Wilson played nearly every day.

According to the a listing by the Metropolitan Golf Association, the last scores the mayor publicly posted where between 2000 and 2002 and ranged between 95 and 121. Mr. Donovan said, however, that while he doesn’t remember Mr. Bloomberg’s exact score in July, he recalls it to be in the “low 90s.” He also said “it’s been years since Mayor Mike shot over 100.”

Meanwhile, Mayor Giuliani, a Republican presidential frontrunner, has a handicap of 17 with scores ranging between 91 and 103 in 2006 and 2007, his postings show.

When asked what advice he gave Mr. Bloomberg on his game, Mr. Mickelson said: “I don’t know where I could possibly do that. I mean, if we want to talk money, it’s not like I’m going to say anything; I’m just going to listen. But we had some good conversations and he’s done some brilliant things with the city of New York.”