An old discussion

[Gwayne's World]

Cross breeding vs. out cross breeding.

What are the pro's and con's of both?

Or is it just a matter of the 'Random Slide?'

I'm a novice in this area and things seem to have bogged down on the forum lately, so I thought I'd bring up the subject yet again.

I'm sure there are many out there who find the subject as baffling as I do?

[Laura Smith]

My understanding is that inbreeding CAN be beneficial, but you better make sure that it's to a damn good horse, because inbreeding can reinforce negative qualities too.
I'm also quite sure that the program only "sees" up to the third generation, so I'm not sure what it makes of horses who are, say, 3x4x4 to something, or even 2x4.
I know the Steward has said that she's especially in favour of inbreeding to really, really nice females...

I play around with inbreeding sometimes, especially to nice mares, and I've had a lot of failed experiments, mostly involving buying cheap fillies with a very nice mare in the first two gens and crossing back to that mare. A 3x3 to Maryland Million or whoever won't matter if the rest of the pedigree is garbage or if the dam just sucks (see: claimer https://www.simhorseracing.com/horse.ph ... ID=1030855 )
I can think of two relatively decent outcomes just off the top of my head, though... https://www.simhorseracing.com/horse.php?HorseID=987852 and https://www.simhorseracing.com/horse.php?HorseID=887401 .

I spent some time the other year with some pedigree data, turf sprinter-wise. Of 20 G1 winners, only three were inbred 3x3 or closer. 12 had inbreeding with at least one of the crosses in the fourth generation, and five had no inbreeding within four gens. That's not a big enough sample size to really draw conclusions from (AND it should be noted that, just due to the way TS pedigrees shaped up over the past ten to twenty years, the main sources of inbreeding are older horses; with the advent of SYM, we are seeing a lot more inbreeding to RFTM within the first two to three gens, so if I were to keep up with this pedigree stuff, I suspect it would look fairly different within the next few years) but it's still interesting...

[Gwayne's World]

My understanding is that inbreeding CAN be beneficial, but you better make sure that it's to a damn good horse, because inbreeding can reinforce negative qualities too.
I'm also quite sure that the program only "sees" up to the third generation, so I'm not sure what it makes of horses who are, say, 3x4x4 to something, or even 2x4.
I know the Steward has said that she's especially in favour of inbreeding to really, really nice females...

I play around with inbreeding sometimes, especially to nice mares, and I've had a lot of failed experiments, mostly involving buying cheap fillies with a very nice mare in the first two gens and crossing back to that mare. A 3x3 to Maryland Million or whoever won't matter if the rest of the pedigree is garbage or if the dam just sucks (see: claimer https://www.simhorseracing.com/horse.ph ... ID=1030855 )
I can think of two relatively decent outcomes just off the top of my head, though... https://www.simhorseracing.com/horse.php?HorseID=987852 and https://www.simhorseracing.com/horse.php?HorseID=887401 .

I spent some time the other year with some pedigree data, turf sprinter-wise. Of 20 G1 winners, only three were inbred 3x3 or closer. 12 had inbreeding with at least one of the crosses in the fourth generation, and five had no inbreeding within four gens. That's not a big enough sample size to really draw conclusions from (AND it should be noted that, just due to the way TS pedigrees shaped up over the past ten to twenty years, the main sources of inbreeding are older horses; with the advent of SYM, we are seeing a lot more inbreeding to RFTM within the first two to three gens, so if I were to keep up with this pedigree stuff, I suspect it would look fairly different within the next few years) but it's still interesting...

Thanks Laura! Helpful to me and hopefully others as well.