first image:
Aggressive style of play but without progression.
The first session drawdown -150, stop and brake for several hours.
The second session of the same style of play and quite easily achieved about 180 units.
second image:
Quiet and slow style of game, also flat.
The first session drawdown -50, an after brake +70 units.
The hardest thing in roulette, how to lose a little.
Experienced players understand what I mean.
Also interesting, the first image Dublin 03-08-2013, the second image is a session Baden Baden in 1962.
Different cities, different countries, different tables, the difference in fifty years, but exactly the same nature of numbers.