grammar - Past Subjunctive vs Future Subjunctive form

What is the difference between the three sentences:

1. If i were to play, i would win the match. (Depicts future tense)


2. If i were to play, i would have won the match. (Depicts past tense)


3. If i were there, i would have helped here. (Depicts Past)

My question is that how do we identify where the past subjunctive is being used and where the future subjunctive is being used?