A good scorekeeper will keep track on a piece of paper. Write the five starters in a column. Cross them off when they leave and enter in the same row the new player. The last five listed are in the game. If there are multiple subs, it doesn't matter specifically who is in for whom. Just cross off the ones leaving and enter the ones entering.

I did that when I kept score and I know some who still do it. I know some don't. At higher level games you might have a stats person who is tracking this.

Other than at the end of the game when I know who leaves to be sure they sit and don't reenter before they can, I don't really care.

Anyone who cares, really.

I can't recall any time where I've seen anyone be super-strict about this, save for rules on max quarters for a player.

When The Ball Is Dead We Must Be Alive ...
 

I wouldn't.

In a perfect world, sure, even if it's not dictated by any mechanic, or by any rule language under Rule 2 Officials And Their Duties.

But I don't officiate in a perfect world.

I've only got one minute (or maybe thirty seconds) for me and my partner to get ready to go in the right direction (and right team) on the throwin subsequent to the intermission or timeout (or who is shooting free throws subsequent to the timeout and how many), check the scoreboard for "important" stuff like how many team fouls on both teams (or the time remaining after a timeout), beckon in any substitutes who "elect" to report, and possibly have a tête-à-tête with my partner regarding anything important or unusual occurring, or about to occur, in the game.

If it was a timeout, we also need some time to properly report the timeout to the table, and possibly notify head coaches when their team has been granted its final timeout. And if it's near the end of the game, we may wish to check with the table to make sure everything is in proper order.

In addition we may have to "dig" players out of the huddles after the warning horn sounds, while also keeping a watchful eye out for substitutes that report too late.

I'm getting tired just writing about our many timeout and intermission responsibilities. No way will I have the time to look for little lights on the scoreboard to decipher who will be "different" after the timeout or intermission and to ask the scorer if they reported. No way in Hell.

If ilyazhito can do that, to paraphrase Cary Grant in the movie Gunga Din, he's "a better official than I am".

Always Listen To bob ...
 

Agree with bob jenkins that it, indeed, can be done.

But how often does even a "good" scorekeeper do this in an interscholastic (high school or middle school) game?

I may be wrong, but I'm guessing not often.

As I've already stated. Over forty-plus years, in literally thousands of such situations, I've never had a scorer tell me, subsequent to an intermission or a timeout, "He didn't report".

Never ever.

Like A Sore Thumb ...
 

Little lights on a scoreboard?

Fuhgeddaboudit!

Too bad figuring out who didn't report wasn't as easy as this:

<iframe width="560" height="315" src="https://www.youtube.com/embed/_Sgk-ZYxKxM" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Long Arm Of the Law ...
 

We've got a great local timer who, immediately after sounding the fifteen second warning horn, yells extremely loudly, "FIRST HORN. NO MORE SUBS".

I love this guy.

Ain't nobody going nowhere near that table to report after that.

Of course, his authoritarian announcement won't keep substitutes, who haven't already reported, from "sneaking" out onto the court with their teammates.

Unless, of course, ilyazhito is standing there saying, "Gotcha".

https://tse4.mm.bing.net/th?id=OIP.z...HU&pid=Api&P=0