Mine runs about 12 times a season. Last season, 13, the one before that 11, the one before that 16. Depends what we're doing!
I will happily run him early in the season in quite a few at once. Normally probably 4 in 4 weeks and then peter it out over april/may post chatsworth then pick up again later in the summer before doing quite a few in the autumn. I won't run him on really bad ground though, no point. I might school round slowly if i feel we need that but usually we dont.
HATE bad ground and there is no excuse for it.
My 4yo is entered for Stratford Hills but won't run if its terrible. Am prepared to risk the money for that. She'll run at the 2 BYEH's she's entered and then there and probably 1 other PAVO. I hope everything will be qualified for then as she'll then be turned away until the finals. I don't believe in running babies hard.
That said we had a 5yo last season who ran quite a lot and got better and better that way rather than being quiet. He got about 10 points and it defintely helped him and he came out well this season from it. Won last week too!
On good ground I don't think you can run them too much afterall my boy hunts twice a week quite often and will SJ on another day in the winter and he survives!!
Hunters, racehorses etc survive with much harder work than many evnters that only run 5 or 6 times a season. Many sucessful eventers raced a fair amount in their past but it doesnt seem to affect their soundness too much.
Of course putting unecessary wear and tear on the legs is unadvisable and we all avoid it if at all possible. However, baby horses do often need the consistancy to learn. Once they understand the game (and they pick it up at different rates) then you can rdeuce the amount of events you do. You'd always want to run an intermediate horse less than a PN horse for health reasons and mental reasons- the pressure sat the higher levels are so much harder. I dont think that running a horse at a sensible speed on good ground in a PN is a particularly strenous thing, so long as youre foundation fitness work is in place.
If I hadnt had exams then Moon would have run 5 times by now, would run 2 or 3 more times at novice level and then have a break when the ground gets hard July/ August. She'd then come out again in the autumn and would do 5 or 6 more at novice. Because this isnt possible and because she isnt perhaps the most natural xc horse there is, she'll keep running through the summer on the best ground I can find and will event every fortnight.