I gotta take issue here with the suggested attribute of 'heart'; some people have suggested you need it to win events or indeed to be successful [same thing in my book].
Let's assume for the purposes of this post, success actually means winning things'.
We can obviously define success in terms of 'enjoying playing' in which case, this doesn't have to have anything to do with winning anything though I am sure Dynasty have enjoyed winning their trophies.
The point here is, a team who has won diddly-squat can still enjoy all of their games and in this sense are hugely successful but as I say, this is not what we are talking about here because in this case, success = winning.
OK, I have a problem with the use of the word 'heart' because I think it's being used in the same context as when it's applied to some other sports such as football and if so, this is definitely not the case.
'Heart' in football terms explains why Scotland can compete [for the most part, though not win] against England ...heart is what explains why local derbies are so unpredictable no matter what the skill differential .... it's all about motivation here because if you have a huge incentive [as the Jocks do when they play us English] then this 'heart' can make them run further for longer, it provides the determination to close down opponents where before, that run may not have bothered to exert themselves to that degree.
The willingness to go that extra mile is so evident in matches such as Scotland v England or Arsenal v Spurs, Celtic v Rangers and so on ...... Heart is a derivative of not wanting to lose ...cubed.... and this type confrontation will always generate that type reaction.
Ironically, 'heart' in this sense, has a huge emotional component and it is this emotion that then goes onto generate heart and if I wanna go 'all biochemical' on your ass, it suggests adrenaline could well provide the hormonal impetus [and energy] for that 'extra mile'.
When we play paintball, there is little opportunity to 'go that extra mile' in terms of on-field behaviours in that same vein as when it's applied to football.
Physical exertion in paintball is sporadic and infrequent, I agree that near the end of the day, people get tired and maybe there we have a small window of opportunity to maybe make that 'extra' run that could be an emergent property of heart but as I said earlier, there is little overall opportunity.
If people want a definitive list that best describes what's needed for a successful team, here is my list.
In no particular order :-
1. Talent.
2. Dedication.
3. Professionalism.
4. Focus [generally provided by the alpha male / coach / owner].
Everything else is peripheral and of lesser importance [IMHO].