Forward test : 1/2, 1/3, 1/4 ?

 

Hi,

Optimizing an EA on a instrument for which my broker owns 2 years, I'm wondering if I'd better use 1/2, 1/3, 1/4 ? Which advantages/inconvenient for each, generally speaking & on my 2 years history's symbol ? (MT5,brokers data only).

1/2 : catch params with better perf on a long 1/2, then matching on a another long 1/2

1/4 : catch params on a long 3/4, then matching a short 1/4

How do you read it ?

Reason: