Traditional formation evaluation in shale plays has been inefficient. As result the operators have been developing shale deposits blindfolded. Some operators have stopped running open-hole log data and are resorting to statistical or geometric drilling and completions. According to industry experts with this approach 95% of shale oil is left in the ground and two thirds of hydraulic fracturing stages do not produce commercially. We found the way to solve this problem developing a technology that uses standard open-hole log data to calculate a Brittleness and Production Profile (PP) that shows predicted production along the entire well. The technology was tested for more than 100 wells in Permian basin. The basic equation for calculation PP was distilled from a unique set of data that included permeability derived from hundreds of hydrodynamic or pressure build-up well tests, and open-hole logs. The equation was used successfully to develop many thousands of wells in conventional reservoirs. Later it was modified for shale plays. Applying the technology to Permian Basin shows that the best producing formations are distributed sporadically with different orientation. This is very significant difference between shale fields and classical conventional reservoirs. The mapping of these best spots is a key to increase oil recovery efficiency for shale plays. PP for vertical wells allow to identify the highest producing formations and the best locations and trajectories of horizontal wells. It removes the blindfolds. After identifying the locations and trajectories of horizontal wells the fracking stages should be identified. Using Brittleness, an operator can calculate breakdown pressure and the cost of fracking each stage of a vertical or horizontal well. The PP shows predicted production of each stage. So operators can calculate the economics of the development and make informed decisions. Analysis of PP in the Permian Basin shows that 80% of the thickness produced 12 times less than the remaining 20%. The technology separates low and high producing formations, allowing operators to avoid drilling of 80% of low producing horizontal wells and drill only horizontal wells with top production. According to recent field study four to five high producing horizontal wells can be drilled at the same location. Applying the technology radically increases operator’s success rate. For example, instead of one horizontal well with initial production 120 Bbl. /day, an operator using PP can drill at the same location two horizontal wells with the total initial production 1,300 Bbl. /day. The technology can also be applied in old wells for refracking and drilling new high producing horizontal wells.