When Mike Tyson steps into the ring Saturday night, he will be 19 days shy of 39. By this age, most fighters have packed it in or their family and friends are begging them to do so. But Tyson’s creditors are telling him after Saturday, he has five more fights to go.

Discussion of Tyson’s decline always brings up familiar topics: lack of discipline, lack of desire, and madman behavior in the ring. One that is usually not mentioned is age. It certainly is a factor. Tyson’s bob and weave, straight ahead attack is a style that few fighters can carry past the age of 27, much less at the age of 39.

Two all-time greats, Joe Frazier and Jack Dempsey, used this strategy in the ring. Like Tyson, the bob and weave assault is perfect for a shorter fighter with tremendous power. Frazier, like Tyson, is 5’11”. Dempsey was 6’1”. Both found their skills leaving them in their late 20s.

“Iron Mike’s” debut onto the boxing circuit in the 1980s left many boxing fans in awe of his blitzkrieg attack which usually decimated opponents before the end of the first round. Jack Dempsey’s emergence in the late 10s and 20s left that same kind of mark and Dempsey scored more first round knockouts than Tyson. He holds the record with 25.

Between 1917 and 1918, Dempsey knocked out 18 of his opponents. In 1919 he dispatched his first six opponents in a total of six rounds. Then he faced the gigantic and seemingly invincible Jess Willard for the heavyweight championship tin Toledo, Ohio in July of 1919.

The 24-year-old Dempsey came out bobbing and weaving and knocked Willard down seven times in the first round. Willard plodded through rounds two and three and then became the first champion to lose his title sitting down when he refused to answer the bell for round four.

As champion, Dempsey fought considerably less but with the same fury. Four of his first five title defenses ended in knockouts. The last of those against Luis Angel Firpo saw Dempsey send the “Wild Bull of Pampas” to the canvas nine times. At that time, he was 28.

Dempsey did not fight again for another three years. He made movies, got married, and waited out his contract with Jack “Doc” Kearns. When he finally returned to the ring against Gene Tunney in September of 1926, he was 31 and had lost a step. The quick and cerebral Tunney was able to hold off Dempsey’s once unstoppable charges and easily win a ten-round decision.

In the rematch, the result was pretty much the same. Except for a 7th round knockdown by Dempsey that became the famous “Long Count,” Tunney was once again able to keep the “Manassa Mauler” and pull out a ten-round decision. Dempsey retired thereafter.

Joe Frazier’s journey was a tad bit different. In “The Fight of the Century” in 1971, “Smokin’ Joe” reached the pinnacle of his career with his unanimous decision over Muhammad Ali. After that, he reeled off two wins over Terry Daniels and Ron Stander before facing George Foreman in Jamaica in January of 1973.

At that time, Frazier was 29. Whether or not his skills had begun to decline is uncertain because a prime Foreman was the perfect counterbalance to the bob and weave attack. Boxing fans know the story. Foreman destroyed Frazier as Howard Cosell repeatedly screamed “Down goes Frazier! Down goes Frazier!”

A year later, Frazier faced Ali, who this time was able to keep “Smokin’ Joe” away to win a boring twelve round decision. Frazier went on to knockout Jerry Quarry, who did not have much of a defense, and Jimmy Ellis, who was close to retirement. He then faced Ali again in the “Thrilla in Manilla.” After that, he faced Foreman again and was knocked out in the fifth round. Aside from a brief comeback in 1981, the Foreman fight retired Frazier.

Had Dempsey and Frazier stayed in the ring as long as Tyson, it is likely that they would have experienced similar success. In other words, they would have beaten good opponents but lost to great ones. Besides the Danny Williams fight, “Iron” Mike has had no trouble with mediocre opponents. It was only the greats, Lennox Lewis and Evander Holyfield, who gave him trouble.

From 1919 to 1927, Dempsey only lost to Tunney, who is one of three fighters to retire as heavyweight champion. Rocky Marciano and Lennox Lewis are the others. Frazier only lost to Ali and Foreman.

Had Tyson not blown his knee out in the fourth round against Williams, he likely would have beaten him too. Williams managed to weather a substantial amount of punishment and came back to knock Tyson out in the first round.

The legs are one of the reasons the bob and weave style will not carry most fighters to greatness into their 30s. They are always the first to go. The loss of that step makes it easier for an opponent with a strong jab to pick off this attack and keep the fight outside.

But if Tyson’s legs can hold, he will probably be able to break through Kevin McBride’s defense on Saturday. Beyond that rests a division of good but not great heavyweight champs. If Tyson can maintain his discipline, he may be able to carry his style a little longer and pick up another belt in the process.