Still doing chess tactics problems: stagnation or progress?

I finished another round through the one-move chess tactics problems. I lost count, but I am probably approaching the magic number of 7 repetitions. I noticed that I certainly recognize more pattern than before, but overall I am still pretty slow. A post at Patzer's Mind linked to an interesting review of a chess tactics training software written by Kjell Arne Brekke. The interesting part of this review is not so much the information on the software (Intensive Tactics Course 2) but the general comments on the psychology of playing chess well.

The article discusses the merits of doing a few hard problems vs. many simple problems. I have been concentrating on the latter approach by solving mostly one-move tactics problems (so far). Kjell Arne Brekke cites several psychological studies of chess players in the review. The main conclusion is, that the number of memory chunks with chess positions seems to be the biggest difference between chess masters and everyday patzers. The average grandmaster memory seems to hold 50000 of these chunks. The article concludes that doing many simple tactical problems is more efficient than a few hard ones because of the higher number of memorized positions.

I estimate that I learned roughly 500 positional chunks in the 5 months I am now playing chess. If I continue at the same rate, it will take me approximately 41 years to obtain the pattern recognition of a grandmaster. This means that I will won't the zenith of my playing strength before I am well into retirement age. But that should be a good time to play chess anyway. The positive consequence of this simple estimate is also that I really shouldn't feel too badly about the blunders I commit nearly every day - learning to play chess well simply takes a much longer time than the 5 months of experience I have!