I apologize for not rememberin= where I first read this, but it was pointed out that if you look at the original saving throw chart a pattern emerges.
You will see see that for all classes save versus death ray/poison are clearly better than save versus staves/spells. It not unreasonable to suggest that given the severity of save or die that Gygax opted to give his player a significant (10% to 20%) break at lower levels.
It appears that Flesh to Stone occupied a middle ground between the two. An effect that takes a character out of play but there is a way to restore them to full functionality (Stone to Flesh).
That wands were considered an advantage compared to memorized spells and thus easier to save against And finally that a dragon's breath was more easily resisted by a fighter than a magic-user/cleric.
Looking at the original saving throws categories this way lead to a straightforward procedure on determining what category to use.
- Use Staves/Spells
- Unless it is something more easily resisted by a fighter than a cleric or magic user then use Dragon Breath.
- Unless it is a Save or Die effect or something similar then use Desth Ray/Poison.
- If it is a incapacitating effect that is reversible then use Stone.
- If it anything but a Save or Die effect and it comes from a wand use the All Wands save.
I still prefer Swords and Wizardry single save with specific bonuses but I appreciate the original saving throw system better now that I took another look.