Toto by mělo fungovat:
Fight::whereStatus('finished')->where(function($q) use ($uid) {
$q->where('user1',$uid)->orWhere('user2', $uid);
})->count('id');
UPRAVIT
Odpověď na komentář:
Fight::whereIn('status', ['finished', 'cancelled'])->where(function($q) use ($uid) {
$q->where('user1',$uid)->orWhere('user2', $uid);
})->count('id');