(Credit, left to right: Library of Congress, Associated Press, Agence France-Presse — Getty Images)

Athletes seem to swim faster, jump higher and throw farther with each passing year, so it’s natural to expect sports records to fall like dominoes. Yet, certain feats in sports — like the rate at which basketball players make free throws — don’t seem to get any easier with time. Which records will be hard, and maybe impossible, to break?

Joltin’ Joe’s 56

Will Carroll is a senior writer at Baseball Prospectus.

“56” will never be broken in baseball. While 61 (home runs in a season) has been passed several times over, and 300 (career wins for a pitcher) remains hard but not impossible to reach, Joe DiMaggio’s hitting streak looks more and more untouchable as every year goes by.

The last serious assault on the streak was Pete Rose, who fell well short. Even Pete wouldn’t bet that today’s baseball player could make that kind of run. While the game has changed, it’s changed in a way that makes 56 even more untouchable.

If Ichiro can’t get near DiMaggio, there’s no one in the game who can.

Here’s a quick number for you: 204. That’s how many strikeouts Mark Reynolds, the Arizona Diamondbacks third baseman, had last season. That broke the record of the Phillies’ Ryan Howard at 199 in 2007. (Howard did his best, striking out another 199 times in 2008 as the Phillies went on to the Series.) DiMaggio never had more than 39 strikeouts in a season and in his 13-year career, he had only 369 K’s. That means Reynolds will pass his career strikeout mark sometime in late April … and Reynolds is just starting his third year in the league.

Even Ichiro Suzuki, a throwback to the “choke up and avoid the strikeout” strategy, hasn’t come close. If he can’t get near DiMaggio, there’s no one in the game now that can. 56? Never again.

It’s the Game That Changes

Allen St. John is author of “Made to Be Broken: The 50 Greatest Records and Streaks in Sports History” and, most recently, “The Billion Dollar Game: Behind the Scenes of the Greatest Day in American Sports, Super Bowl Sunday.”

Sports fans love records because they provide a kind of shortcut in any argument, and never so much as when it comes time to compare contemporary athletes to the legends of yesteryear. Resolved: these guys today couldn’t shine Babe Ruth’s spikes.

The reality is that if an important record in sports endures year after year, decade after decade, impervious to every attempt to top it, it’s not because athletes are regressing. It’s because the game itself has changed. Sometimes these fundamental changes in a sport are obvious. Why is Cy Young’s career record of 511 wins totally untouchable? Because in modern baseball, pitchers have to throw harder, and there’s no way for Johan Santana to pitch as much as Young and his contemporaries.

Athletes don’t make evolutionary leaps in four decades. It’s a matter of technique.

Sometimes the changes aren’t so obvious. Why does Joe DiMaggio’s consecutive 56-game hitting streak seem unassailable? In part because he set the record when baseball was still a segregated sport, and standout pitchers like Satchel Paige were plying their craft in the Negro Leagues.

The natural counterpoint can be found in sports like swimming, where world records seem to fall every five minutes. How does Michael Phelps stack up against Mark Spitz? Spitz’s 1972 Olympic and world record time in the 200-meter freestyle would have been too slow to even make the men’s field in last year’s games.

(Photo, top to bottom: Doug Mills/The New York Times, Associated Press)

This is not to say that athletes like Phelps have made an evolutionary leap in four decades — Darwin knew that natural selection doesn’t work nearly that fast. It’s simply that swimming is a technique sport, and Phelps and his generation of swimmers are the beneficiaries of years of sports science and simple trial and error.

For a more reliable yardstick of athletic progress, look to the world of track and field, where Lee Evans’ 1968 Olympic and world record in the 400-meters remains the seventh fastest time ever, only 7/10s of a second behind Michael Johnson’s current world record.

The reality is that, as a whole, today’s athletes, with the benefits of better training, advanced equipment and improved sports medicine, have pulled away from their predecessors slowly but surely. Certain sports, on the other hand, have made great leaps forward — or at least sideways. And that, sports fans, is why some pages in the record book will continue to change at a dizzying pace, while others will likely remain the same for decades to come.

The Impossible Takes a Little While

Ray Stefani is a professor emeritus at California State University, Long Beach.

Are we reaching a plateau with sports performances? We know that some combination of four factors — physiology, advancements in technique, coaching and equipment — leads to improved performance. For records to stagnate in any event, all four factors would have to stop being improved.

So what do we make of the fact that track and field performances have essentially stagnated since the 1988 Seoul Olympics? For example, only 32 percent of the Olympic track and field champions at Sydney in 2000 would have won in 1988. Similarly only 44 percent of similar champions in 2004 and 50 percent of those in 2008 would have won in Seoul.

Of course, we should remember that Ben Johnson was disqualified in 1988, followed by a dramatic increase in drug testing. And it has taken 20 years for reasonably clean track and field athletes to match some of the drug-tainted performances in 1988. But running events, even in good times, typically have only about one-third the rate of improvement of throwing and swimming events. Usain Bolt’s dramatic wins at Beijing were part of the renewed improvement in track and field events compared with 2004.

Back in 1924, some probably wondered if anyone could significantly improve upon Johnny Weissmuller’s 67 world swimming records (more than Michael Phelps and Mark Spitz combined), and he was never beaten. In the 1924 Olympics, Weissmuller famously beat the Hawaiian father of surfing, Duke Kahanamoku, at 100 meters in a time of 59 seconds.

It would have been unbelievable to that generation that one swimmer, Oussama Mellouli of Tunisia, won the 1500 meter in Beijing in a time of 14:40.84. In 1924, it would have taken a relay of 15 Weissmullers to swim the 1500 meter in 14:45 — which would still have been slower than one man in 2008.

What the 1924 observer would have deemed impossible happened, and that effect may be true for observers from every age. It’s reasonable to assume that “Citius, Altius, Fortius” will continue to describe future athletic performance.

No Horse Like Big Red

Ray Paulick, former editor in chief of The Blood-Horse magazine, is editor and publisher of the thoroughbred racing Web site, Paulick Report.

The great Secretariat, winner of the 1973 Triple Crown, still holds several of the longest-standing horse racing records — and they could last well into the future. Big Red still has the fastest time ever in the Kentucky Derby (1:59 2/5, for the mile and one-quarter) and Belmont Stakes (2:24, for the mile and one-half). The electronic timer malfunctioned in the Preakness Stakes, so there is no official time for Secretariat in that race; his unofficial stopwatch recorded time does not count.

(Photo: Associated Press)

The closest any horse has come to his Belmont Stakes record was in 1989 with Easy Goer, who was still a full two seconds slower than Secretariat when he beat Sunday Silence in the Belmont. Monarchos came within two-fifths of a second of his Kentucky Derby record in 2001.

Even more amazing than Secretariat’s final time in the Belmont was his margin of victory — 31 lengths. The great Man o’ War won the Belmont by 20 lengths in 1920 and Count Fleet was 25 lengths best in 1943, but no horse has come anywhere near that achievement since Secretariat’s win. (His son, Risen Star, won by 14 ¾ in 1988). His 31-length margin may be the safest of all racing records. Of course, just as a tape-measure homer only counts for one run in baseball, a huge winning margin in a horse race doesn’t get you anything more than a nose victory does.

A human record from the Triple Crown is the five consecutive victories in the Belmont Stakes by horses conditioned by Hall of Fame trainer Woody Stephens, starting in 1982 with Conquistador Cielo and continuing through 1986, when Danzig Connection gave him the win. It would be difficult to imagine anyone ever putting together a similar streak.

What if the Greeks Had Stopwatches?

Allen Guttmann, a professor of English and American Studies at Amherst College, is author of “From Ritual to Record” and 10 other sports histories.

No one in ancient times worried about how long it took before someone broke an Olympic record because no one in ancient times understood the distinctively modern concept of a sports record. There was no way to talk about a runner’s or a discus thrower’s unsurpassed athletic performance because the Greeks and Romans never bothered to measure times or distances.

With one interesting exception, they never attempted to quantify athletic achievements. And without the numbers there was no way to compare achievements from one Olympiad to another or from one place to another. Did the winner at Olympia run the “stade race” (one length of the stadium) faster than the runner at Athens? No one knows and one reason no one knows is that the stadia were of different lengths (just as all the discuses were of unstandardized weights).

Talk of sports records and stats only began in 17th century England with the age of Newton.

“Man was the measure of all things” and there was no need to measure athletic achievements. The main exception to this view occurred in Roman chariot racing, where there was a careful count of the number of victories chalked up for every charioteer (and for every horse). But everyone knows that we are a lot more like the practical Romans than like the aesthetically inclined Greeks.

When and where did people begin to measure sports achievements and talk about records? In England, toward the end of the 17th century. It is no accident that the mania for measurement came at the same time as the scientific revolution associated with the name of Sir Isaac Newton.

And once people decided to measure sports performances as well as the orbits of the planets, inventors produced the necessary instruments. Stopwatches, for instance, were invented early in the 18th century — in order to time horse races — and from then on we were, figuratively speaking, off and running. If there are sports anywhere in the modern world where no one calculates the “stats” and no one thinks about records, let me know.