The 1st rankings were in a 1925 Ring Magzine but they were just rankings not P4P.

In 1989 after Tyson beat Spinks the Ring came up with a list of the P4P fighters. I personally believe it had more to do with Tyson. But who knows really.

I help out in the wikipedia page of the ring magazine and add ratings to it myself I've got lots of old ring magazines and every now and then I'll add something to it.

In 1989 the 1st P4P list looked like this:
Tyson
JCC
Pernell
Nunn
Esparragoza
Meldrick Taylor
Nelson
Raul Perez
Virgil Hill
Marlon Starling

As you can clearly see the P4P list was not a good one having left out fighters like Zaragoza who at that time was unstoppable, How about some love for Evander who was the Undisputed Cruiser and moved up to HW?
Koo Chang was a long reigning champ and got no love on the 1st P4P list.

Anyway...

JCC was P4P #1 from 1990-1992
Pernell was P4P #1 from 1993-1995
From 1996-1999 it went like this RJJ 1996, ODLH 1997 & 1998 and Pernell 1999.

So overall Pernells been #1 for 4 yrs. 3 of which were consecutive yrs.
Anyone interested in seeing these rankings can navigate through The Ring Magazines wikipedia page theres lots of lists and rankings there you can navigate thru.
Here: The Ring Magazine - Boxrec Boxing Encyclopaedia


Annual ratings: The Ring Magazine's Annual Ratings - Boxrec Boxing Encyclopaedia