Forum:Keep losing in Arena

I didn't participate in the first Arena but decided to join this one, arena 2. I think I just don't understand what to do to win. What is a win based on? Is it the number of heros you have or equipment you have or what? When I battle its not that hard. You see the number of people a person has in their army, what level they are etc. and to me that makes it easier for someone who does not play facebook games everyday. By having the chance to look at how many members are in someones army and, for instance, if they have a low number and around the same level as I am I assume most of the time they probably have about the same stuff I do and maybe 9 times out of 10 I win when doing a regular battle. But the arena you see their rank and level. I have won more than lost (71 wins and 28 losses) but I'm just trying to find a strategy I suppose. I have battled people that have lower rank and lower level than me and lost. I've battled people with higher battle rank and higher level and won so I'm not finding anything other than dumb luck that would help me know who to click on and who not to. I've not be one to buy tokens to purchase heros and chest other than when I've earned the tokens to buy them by completing achievements in the game. Is that what it takes, buying the best heros and chest to winning the arena?