It is best to observe 20 spins or so, to identify which strategy to apply. This is exactly what I meant. 30 spins are sufficient to give you a good indication. Only if you observe a drastic change in the trends. Again, in such cases, it's best to observe 20-30 spins before applying a system.
All systems created for the dozens are applicable for the columns as well.
Observing the trends is again necessary, as columns may tend to repeat while dozens alternate in some cases. In case there are fluctuations, it may take an extra hour for recoveries, if you are playing in a real casino. On the Internet it goes much faster, although the betting amounts are lower. Question All your testing seems to have been done on a single zero Roulette wheel. The zeros appear as 0 in the simulation table, whether they are single or double zero, as I ran simulations for both European and American roulette wheels.