Waddup I'm Jared, I'm 19 and I never fudging learned how to read.
If my horse joins a competition you were using to BLUP with fillers, it's because either no empty competitions were available or I believed there were two non-filler horses already.
Sorry if this happens, I try to avoid it but it will inevitably happen sometimes since comps are open to all users. I'm just trying to BLUP my horses, same as you. Drop me a message if you need me to wait a few minutes for you do be done
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