By Tim Smith

World Boxing Council heavyweight champion Wladimir Klitschko is a deceptively big man. You see him from afar and he does not look so big or imposing. But the closer you get to him, the bigger the 6-6, 240-pound Klitschko gets.

Calvin Brock is not a small man himself, going 6-2, 230 pounds. He does not see Klitschko as overly imposing. But he will get a closer look when the two meet in the center of the ring at Madison Square Garden on Saturday night (HBO at 10 p.m.).

“His height is not a big deal,’’ Brock said on Tuesday following a brief noon time workout at Grand Central Station in Manhattan. “It’s all about skill, conditioning and timing. Believe me the height will not make a difference.’’

Brock is counting on his past experience against bigger, taller opponents. Most recently Brock scored a sixth round knockout of Zuri Lawrence (6-4) on Feb. 25. Before that Brock won a 10 round decision against 6-6, 265-pound Jameel McCline in 2005. Brock got up off the deck in the seventh round and still won the fight. It was a match that made Brock a serious contender.

That was the only serious test that Brock has faced in his career. For the most part the road to his 29-0 record (with 22 KOs) has been smooth.

On the other hand, Klitschko (46-2, 43 KOs) has had his share of ups and downs. He won his first heavyweight championship by winning a 12-round unanimous decision against Chris Byrd in 2000. He was able to put together five straight successful defenses over the course of three years before things went south. Klitschko was knockout in the second round by Corrie Sanders, a South African journeyman who was preparing to begin a pro golf career before meeting Klitschko for the title.

That loss was considered a blip on the screen. Things didn’t reach a critical stage until Klitschko lost to Lamon Brewster in a match for the vacant W.B.O. title on April 10, 2004. It appeared that Klitschko ran out of gas in the fifth round before getting stopped by Brewster.

That loss raised questions about Klitschko’s stamina, his chin and his heart. He said he never lost his confidence.

“That second loss (to Brewster) was a mystery,’’ Klitschko said. “I never could figure out why I lost. I knew I would get back. I never thought about quitting or losing again.’’

Trainer Emanuel Steward got Klitschko back on track by convincing him to stick to their game plan no matter what. It proved to be valuable advice against Samuel Peter in an International Boxing Federation and W.B.O. title elimination match on Sept. 24, 2005.

“He never deviated from the plan,’’ Steward said. “Even when Samuel Peter got knocked down three times he got up and stuck to the plan. It was like he had a navigation system.’’

Klitschko came full circle when he met Byrd again for the I.B.F. title in Mannheim, Germany on April 22. There were some knockdowns, but Klitschko wasn’t the guy getting up off the canvas. In one of his most dominating performances as a heavyweight, Klitschko hammered Byrd. Klitschko won on a seventh round TKO.

Steward said that Klitschko’s size had nothing to do with his victory over Byrd.

“It was his hand speed,’’ Steward said. “Byrd told me that he never saw some of the punches coming. I’ve heard that from some of his other opponents. He’s got that fast left jab and then he follows it with the right hand. A lot of guys after the fight are asking, “What did I get hit with?’’ They don’t see the right hand. And it’s a powerful right hand.’’

So, Brock is right. It won’t be the size difference between himself and Klitschko. But the difference in the fight will be whether Brock can adjust to Klitschko’s speed and avoid the power behind the right hand. And whether Brock will be able to deliver his own November surprise – a powerful right hand of his own.