Mike Tyson had a better career than Larry Holmes.

Let's dispel this myth since Holmes is treated like royalty around here.

A. Their common opponents during their reigns are as follows
1. Berbick--destroyed by Tyson, W15 by Holmes
2. Bonecrusher--UD for Tyson, late TKO for Holmes
3. Williams--KO1 for Tyson, competitive decision for Holmes
4. Spinks--KO1 for Tyson, 2L's for Holmes
*Thomas--Destroyed by Tyson, Holmes didn't want it.

"But NoNeck, they were old for Tyson and Holmes was past prime when he fought them."
--This is a convenient set of excuses, of which Holmes is granted many.
1. Berbick was coming off the best win of his career for Tyson and held a belt. Berbick was 18-1-1 for Holmes and had done nothing of note except beat a past-it Tate. Edge Tyson.
2. Bonecrusher was coming off the best win of his career against Witherspoon and held a belt for the Tyson fight. He was close to a novice for Holmes. Edge Tyson.
3. Williams had beaten Berbick in an eliminator and Rouse and Ferguson in the couple years preceding the Tyson fight. Williams was little known for the Holmes fight and got his number called because he was dropped by Quick Tillis. Edge Tyson.
4. Spinks was the lineal heavyweight champion for the Tyson fight, not old, and entered the ring as a 4-1 underdog against a peak version of Tyson. Spinks entered the ring as a moving up light heavyweight against Holmes and entered the ring as an underdog (source for odds needed). Edge Tyson.
1a. Holmes was prime for Berbick.
2a.--4a Holmes had started to age, but Bonecrusher, Williams and Spinks were all cherry picks in comparison to the other challenges out there, such as a seasoned Witherspoon and Pinklon Thomas.

B. Mike Tyson knocked out Larry Holmes
"But Noneck, Holmes had a two year layoff and wasn't as good as when he beat Mercer."
--This is also false. Holmes fought Tyson I year and 9 months after losing to Spinks, meaning he wouldve been training just 1.5 years after losing to Spinks. This is a common layoff for elite heavyweights, especially aging ones, and I do not need to dig for similar examples.
--I asked for examples of fighters coming back in their forties and being better than in their thirties, and received no valid answers except for a guy who came back after a decade off in his late thirties, which does not provide a similar example.

"But Noneck, Holmes still would've beaten Tyson if Holmes were prime."
--Holmes got dropped like a sack of **** by Snipes and Shavers during his prime with the same shot Tyson landed.

C. Quality of title defenses
--Tyson made ten solid ttitle defenses. I think they all were top 5 in the division according to the Ring except Seldon, who was 6 (due to Tyson being top 5) Bruno, who was top ten, and Biggs, who was highly regarded Gold medalist and top ten.

This basically a lean cut of beef, no fat sticking out.

- -Holmes successfully defended against top tenners Evangelista, Ocasio, Shavers, Leroy Jones, Zanon, LeDoux, Berbick, Cobb, Witherspoon and top fivers Weaver, Cooney, and Bey. Edit: Cruiserweight Ocasio might have been top 5 according to @Unforgiven (6/23/21)

When I look at this line-up it stands out to me that Holmes was habitually fighting easy touches and the competitive matches like Witherspoon and Williams were due to overlooking green opponents, no rematches given. Weaver and Cooney were, for the most part the only intentionally difficult fights.

D. Title winning efforts.
--Tyson beat Berbick, Bonecrusher, Bruno, Seldon, and Tucker for titles, and won the lineal belt against Spinks. Holmes beat a last legs Norton who didn't actually win a belt in the ring and took lineal against a Parkinsonian Ali.

No analysis needed here to determine which is more significant.

E. Nontitle wins
Ruddockx2, Stewart, Golota, Mathis Jr, Botha, Marvis, Mitch Green, Ribalta, Ratliff>Shavers, Mercer

"But NoNeck, Tyson lost to Douglas in his prime."
--Good for you. Here's a cookie and a pat on the head.

Conlcusion: Mike Tyson deserves to be ranked ahead of Larry Holmes.

Late Additions (6/23/21):
1. Men who Holmes did not fight:
Dokes was Ring annual number 4, 3, and 1 for 80--82.
Coetzee was 8 in 78, 3, in 79, 5 in 80 and 81, 1 in 83, and 5/6 in 84/86.
Tate was second only to Holmes in 79
84 and 85 belonged to Pink, number 1 in each year.
Page was 2 in 83 and 84, and 5 in 85

2. Other than Williams, who was denied his owed rematch against Holmes, every man Tyson beat during his title run in the 80s either won a heavyweight title or Olympic Gold. That's 9 men.

Holmes, during his title run, only beat 6men who won a heavyweight title and/or Olympic Gold in a boxing ring. Tyson, coincidentally, beat two of those men when they were champions and a third was a Parkinsonian, Thyrolar riddled Ali, which doesn't count for much.