The difference in size and speed between today’s players and those of my childhood (I’m 44) is astronomical.
Look, back in the late Sixties and early Seventies, when I started watching the NFL, Buck Buchanan of the Chief was 6’6" and 275 pounds. He was regarded as a monster. Nobody else in the NFL was that big.
Today? Buchanan might be regarded as an undersized lineman.
In 1971, Alan Page of the Vikings was the league MVP. He was a perennial All-Pro, and was considered everything you’d ever want in a defensive tackle. He played at 230 pounds! Today, he’d be considerd too small to start on most college teams (and a few high school teams, for that matter).
Now, in fairness to Page and Buchanan and the other NFL stars of the Sixties and Seventies, if they played today, they’d be eating better and working out constantly, and could have gotten much bigger. But the fact remains, if you just pitted the current Patriots against the 1967 Packers, the Packsers would be steamrollered. Bart Starr wouldn’t be prepared for the speed of the pass rushers (to him, pass rush meant Bob Lilly- he couldn’t have conceived of a linebacker with the speed of a Lawrence Taylor). Jerry Kramer and Forrest Gregg couldn’t have opened holes against a modern defensive line. And the complexity of modern defensive schemes would have baffled the Packers.
As for baseball, well, when I was a kid, most teams had one or two guys with biceps and with the power to hit a ball out of the park regularly. Shortstops and second basemen were skinny guys who weren’t expected t ocontribute much with the bat. Heck, if a shortstop or second baseman had a decent glove, that was enough to keep him in the lineup (if he could hit .250, that was a bonus). Today, EVERYBODY has biceps and six-packs! When I was a kid, a pitcher figured he was safe if he could get down to the bottom of a lineup. Today, shortstops and second baseman are often dangerous hitters, too! A pitcher rarely gets a break or an easy out in modern baseball.
Again, over time, the players of the Sixites and Seventies would have made transitions (some of them DID- Nolan Ryan was successful in the old days AND in fairly modern times)… but if all you did was put the current Yankees in a time machine and had them play the 1961 Yanks… the 1961 Yanks would’ve been crushed.