Winners Vs Losers Analysis

The following is an image of a trader's winners vs Losers analysis on an hourly basis.

The traders has a track record of 50% win rate at 10 am which is London Open

but 70% Losers during the 1600 hrs which is US Session.

The BIG QUESTION IS

What time should this trader be trading?

This trader trades the DAX30 / German 30 Stock Index at the London Open and Later he trades US30 / DJIA / Dow30 during the US Session. 

Now Let's Compare to that, the following. 

This is an image of a trader's performance by the hour. She trades the DAX30 only. Mostly during the first hour of the London Session.

Look at the Stats on the screenshot and then Question ...

Does this trader even need to trade past the first hour of the London Session?

Have you ever done an analysis of your performance like this?