I don't spend much time on YouTube, but my TV (which knows I'm a gamer) recommended Professor Dungeon Master's year-old interview with @lukegygax about his father's house rules and DMing style.

I have some thoughts.

https://youtu.be/NBqdVDP6dDk?si=cv6gCOzZ9sWohZeN

Gary Gygax's SECRET D&D Rules Revealed At Last! (Ep. 371)

YouTube

#GaryGygax himself might have objected to the phrase "house rules." As far as he was concerned, the creator of #ADnD didn't have #houserules. He only had new rules he hadn't told the rest of us about yet.

https://www.dragonsfoot.org/forums/viewtopic.php?p=198508&hilit=house+rules&sid=76985165b6504d2264b3860ad48a8629#p198508

Oddly not discussed in this interview is a new #ADnD rule #GaryGygax mentioned a lot in his last years: Breaking initiative ties in favor of the character with the longest weapon.

https://www.enworld.org/threads/q-a-with-gary-gygax.22566/post-1401699

This "house rule" is, in effect, a generalization of the initiative rule buried in the #ADnD "charge attack" rules, superseding the Speed Factor-based tie-breaker rule (mentioned and misinterpreted in the previous screenshot). Both rules are on page 66 of the DMG.
(The phrase "longer weapon/reach" is a classic example of Gygax's "common sense" design. Your fighter tied initiative with an Owl Bear? Your 12-year-old DM can use common sense to figure out the monster's reach, because that ain't in the Monster Manual!)

Speed Factor is, as Luke points out, an #ADnD rule that Gary dropped from his own games immediately, so it's not surprising he created a new tie-breaker rule.

In fact, Gygax disliked Speed Factor so much that he was planning to remove it from the game entirely!

https://www.enworld.org/threads/q-a-with-gary-gygax.22566/post-3494968

I still play with Speed Factor, of course, because I'm THAT #DungeonMaster. I actually think #GaryGygax wrote better rules than he realized there, but that's an argument for another day.
Anyway, the interesting thing about replacing Speed Factor with Weapon Length for breaking #ADnD initiative ties is that two systems will produce completely opposite results!
In the Speed Factor rules, *smaller* weapons are "faster," because they're easier to handle than larger weapons. So the rules-as-written generally break ties to the benefit of the combatant with the smallest weapon.
Favoring longer weapons obviously gives the advantage to the combatant with the *least* small weapon. Gygax completely reversed how ties break in his #ADnD games, but that change never made it into the rulebook.

I think most game designers would avoid a revision so diametrically opposite of the original rule, but #Gygax wasn't always that dogmatic. As he often said in his later years, #ADnD is a game not a combat simulator.

https://www.dragonsfoot.org/forums/viewtopic.php?p=247547#p247547

#Gygax either changed his mind about the most realistic way to break initiative ties, or simply didn't care. That's #TTRPG #gamedesign for you: sometimes you design for realism and sometimes you design for expediency.