Streak 'not a big deal' for Justin Smith

Justin Smith turns 150 consecutive starts old Monday. Don't bother throwing Smith a welcome party to the NFL's sesquicentennial club, because the 49ers pass rusher would just the same pass.

"I really don't understand what the big deal is, personally," Smith said. "Really, it's not a big deal."

Not a big deal? All Smith has done the past 10 seasons is start 149 straight games, including the past three as the 49ers' top tackler on the defensive line.

His start streak is nearly double the next in line among all active NFL defensive ends. His is the seventh-longest current run for any NFL player, and the third longest by a defensive player.

Smith obviously has done something right because, for the love of Cal Ripken Jr., the Bengals and 49ers wouldn't have kept trotting him out just because.

"I mean, I guess I've been lucky and fortunate not to be injured too bad to this point," Smith said between shrugs.

Too bad? Smith is a walking injury report half the time. He just hasn't met a medical condition worth taking a Sunday off.

"I've had my ribs separated and my fingers broke and the top of foot broke," said Smith, who didn't deem this year's cut hand and elbow injuries in 2009, 2008 and 2005 worth mentioning in his mental medical chart.

"A lot of guys play through a lot of stuff that you wouldn't believe. Usually it takes something like a major muscle tear or major knee or breaking a bone. I've just been fortunate to not get those.

"There's been times I've had my ankle rolled up and maybe it should've broke, and for whatever reason it didn't, so I'm just thankful for that."

Know what Smith does get? Tackles, and lots of them for his position. His 45 tackles are fifth-most by an NFL defensive end this season, and his 643 tackles since 2001 are a league-best for a defensive lineman.

His five sacks and 10 tackles for a loss lead the 49ers. So do his unofficial 31 quarterback hits and 44 quarterback pressures.

The Niners defensive staff has a defensive points system. Smith is on top of the chart, not Pro Bowl inside linebacker Patrick Willis.

How's that for a thirtysomething who hasn't taken a game off since the first game of his rookie season (thanks for nothing, 50-day contract holdout).

"We try to give him some snaps off, but he's a football player," Niners defensive coordinator Greg Manusky said. "He's been that way since he's gotten here."

Smith can't believe it's been 10 years since the Bengals picked him fourth overall, and he especially can't believe it's been 31 years since he was born on a Missouri cattle ranch.

The defensive end known for his high motor knows he can't go high speed forever. Veteran smarts help him make up for any lost speed, but he said "it's not going to solve if you're slow."

Smith isn't slow yet. He's just slowing down mentally to take in the countryside of his NFL career.

"I'm having more fun with it, enjoying the guys and trying to remember more instead of just, 'Let's go, let's go!' and the next thing you know, another year's gone," Smith said. "I know I'm coming to the end, maybe three or four years left, tops. As fast as the other 10 have gone, that's going to take too much time."

Smith knows one more way to keep his starting streak on a roll. Don't ever sit long enough for the team to discover there are other options on the roster.

"Never let them see your backup and then you can stay for awhile," Smith said.

E-mail David White at dwhite@sfchronicle.com.

This article appeared on page B - 1 of the San Francisco Chronicle