Rightly said in fact even if there is good research on gambling no one can guarantee victory depends entirely on luck. Many times it is seen that no one can win even after doing good research and many gamblers win on the first bet so it is nothing but luck. Research is needed, through research you can learn a lot about gambling you can find out a lot of information. Also knowing the recent form of the team or players their style of play their weaknesses and their history of playing against each other can make betting easier.
Yes, but often this is not enough, as you have seen from the recent events that I mentioned before.
Sometimes unfortunate or luck destroy your plan or bet or what you've simply done.
In the long run I don't know if luck or strategy wins.