Option Trading Articles: [ConservativeOptionStrategies] Back Ratio Put Spread For Protection

This seems to offer great protection with SPY @ 116.17

Buy +2 SPY Jul 116 PUTS
Sell -4 SPY Jul 109 PUTS
Credit .39

Break Even 101.62
Max. Profit $1477

So if on July 17th SPY is:

Above 116 profit $78
At 114 profit $475
At 110 profit $1278
At 109 profit $1475
At 106 profit $880
At 104 profit $478

My question is at what point would you roll down to protect yourself form a major market correction? I was thinking half between current price and breakeven ....say 109.

Leo