I manually programmed a Renko strategy for DAX trading on the 1 min and 15 minute charts myself, and it turned out that Renko charts cannot be used for automated trading. This is because of an inherent priciple : The result depends entirely on the precise closing value of the FIRST bar chosen. So, for example, for the DAX this means you will get totally different results whether you start with an initial upper value fo your first Renko box of 11000.0 or 11001.0. This is because the Renko box size remains fixed to a certain value for the whole chart, and so values for e.g. the upper Renko limit of a box (10 points size) can be only 11010.0, 11020.0 or 11030.0 when starting with an initial value of 11000.0, or 11011.0, 11021.0 and 11031.0 when the first Renko box is started with a value of 11001.0. This may seem as a minor difference only, but it turns out it is not. Trading decisions in the course of a Renko system will entirely change their course for slightly different initial values of the first Renko box.
For point and figure charts I suppose it will be similar, because the box size in these charts remains fixed to a certain value througout the whole chart. So, everything depends exactly on the initial conditions that will never adapt to some convergent value as in most other indicators. Renko charts do look good optically, but cannot be used for defined trading.
Compare the ZigZag indicator ! It also looks perfect (in hindsight) but is in fact completely useless for trading, because it can change direction backwards during the chart evolution.
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