In your opinion, does the success of a team mostly depend on the leadership of the leader or the attitude and performance of the whole team?

Dont think that you are a leader..Be one among the team. A good leader is the one who can develop the attitude of the team and make the whole team perform well.

For me, it takes two to tango and at the same time, it is a collaborative effort. However, I must put a heavy weight on the Leadership part and attribute the success and recognition to the team behind. It is possible that you are a good strategist or planner but you suck at directing, handling and dealing your teams.

Examples:

a.) instead of leading your team to reach GOAL A, you're just bossing around demanding with no proper expectations whatsoever.

b.) if there is/are challenges along the way, you're not right there because you do no know the ins and outs of the business

c.)  You do not give real-time feedback, real-time assistance, and follow-ups regarding the status of your GOAL, instead you just sit and sit and sit looking at your computer the whole day. Remember you are not paid to sit down, you are paid to lead a team.  

d.) You do not know how to  utilize or maximize your resources. Admit it you have employees who are aiming or a leader in them. So, instead of letting them achieve their quotas or targets to make their appraisals look good; why not as early hone them to be a leader, to be the next you in the making- a protege which will become your legacy. Give your people responsibilities or task that in time when they apply for a position they can relate, able to provide concepts and know what they are talking about.

e.) learn to negotiate and fly with your team, if you think your people's plate is already overflowing learn to say NO! and if you can't say no learn to haggle for them may it be in terms of monetary, prices and rewards, citations or what-have-you. 

To summarize, just be a hands-on leader, sail with your team, don't be scared to share or give the knowledge and skill you have and most importantly never claim the whole success of the team. Give where credits is due. After all, the success would not be possible if you do not have a team working for you.