Editor's note: Bob Greene is a best-selling author whose new book is "Late Edition: A Love Story."
(CNN) -- So what an unexpected bit of good luck this is:
I'm going to get the chance to have my completely unsophisticated football question answered.
Sitting two tables away from me in a restaurant is Al Michaels, the superlative sports broadcaster who is the play-by-play man on NBC's Sunday night National Football League telecasts. Having dinner with Michaels and his wife is Andrea Kremer, the sideline reporter for the Sunday night games.
The football question is one so simple and basic that the prospect of actually asking it seems almost pitifully naïve. But, ever since a stranger brought it up to me several weeks before, I'd been thinking about it.
I had been watching a Sunday night game on television in a public place, and after a defensive player slammed into a ball carrier, like two speeding trains bashing head-on, the person next to me said:
"When did they stop tackling?"
I knew exactly what he meant. In recent years, the time-honored tackle -- a defender bringing a runner down by wrapping his arms around him and pulling him to the ground -- seems, to a casual observer, to have become an endangered species.
Instead of classic tackling, professional games are dominated by bodies smashing into bodies, by a defender flat-out leveling a runner, like a wrecking ball banging into the wall of a building.
Conversations about football, especially at this time of year, when playoff positions are being determined, tend to center on minutiae: which teams have a shot at wild-card positions, which quarterback is throwing a surprising number of interceptions.
You'd seem not very wise in the ways of the game to give voice to that oddball question:
"When did they stop tackling?"
But there was Al Michaels, 20 feet away in the restaurant. There was Andrea Kremer.
I knew both of them a little bit: well enough not to feel inordinately bad about interrupting their dinner to ask a stupid question.
Mrs. Michaels, though, I did not know. When I walked over the first thing I did was apologize in advance to her. "This is all you need to be hearing about while you're trying to enjoy your meal," I said.
She was very gracious. So, to Michaels and to Kremer, I said:
Well, you know what I said.
Michaels listened, sat silently for a moment, then said:
"When did who stop tackling?"
"Everyone," I said, and went on to explain the question as it had first been presented to me.
"Bigger, faster, stronger," Michaels said.
He was talking about today's players. He said that, although archetypal tackling still goes on, there is an irrefutable competitive reason for defenders hurling themselves into ball carriers instead of trying to pull them down.
"The idea is to separate the runner from the ball," he said. "This is the way it's done."
Meaning the potential payoff from a standard tackle is not as great as the potential game-changing payoff from a speeding body hurtling into a ball carrier.
Andrea Kremer said: "The teams don't really practice tackling as much. There's not as much value put on it."
She was referring to tackling of the old-time variety. The contemporary body-on-body method of knocking a runner down, she said, "is based on the gamble -- when you decide to try to stop a runner that way, you're gambling that you're going to jar the ball loose."
Michaels said that this development has nothing at all to do with today's players lacking the skill to tackle in the conventional sense. "The players today are the best they've ever been," he said.
And he said that even my assumption that the non-tackle tackles are a new feature of the game is open to debate.
"Trust me," he said. "You'd like to believe that 20 years ago, they were tackling in the old way, but it's been like this for a long time."
Apologizing once more to Mrs. Michaels for the intrusion, I returned to my own dinner. But there was still one more voice I wanted to hear on this subject: one person who, if I was way off base, I knew would not hesitate to tell me so.
Thus, the next day, I spoke with Bob Costas.
"I've had the same thought for years," he said.
There are still any number of old-style tackles in a given game, he said. But the asteroids-colliding, body-on-body crashes have begun to dominate, and Costas said he believes there is a seldom-considered reason for it.
"There has been a perverse unintended reverse effect of football equipment being improved to the point where it's as good as it is today," he said. "The equipment is so excellent these days that the defenders feel invincible. They have so much confidence in the equipment they're wearing that they turn their bodies into human projectiles."
As dumb as my question may have been, recent announcements by the National Football League put it into a not-quite-so-dumb perspective. The league is instituting strict new rules intended to prevent long-term health problems among players who suffer concussions.
Players who show signs of having sustained a concussion during a game or practice must be removed from the field, and not be permitted to return the same day. Those human projectiles Costas spoke about may be effective weapons, but the NFL seems intent on putting less value on the projectile part, and more value on the human part.
Not that this will necessarily herald a return to 1920s-style tackling.
"It's entered the language," Costas said. "Think about it. You don't hear many references to 'So-and-so with the tackle.' It's more likely to be 'So-and-so with the hit.'"
The tackle -- both the act, and the word -- will never entirely disappear.
It's sort of like when those of us in the nonfootball world speak of using a telephone.
We're likely to say we dialed a number, when in fact we are "dialing" nothing.
Same with tackling.
Or, as John Madden used to say: "Boom!"
The opinions expressed in this commentary are solely those of Bob Greene.