The Duel Series of Osprey Military History is interesting in pairing two military technologies (such as tanks, airoplanes or ships) which encountered from opposite sides of a conflict in some point in history. These duels provide insight in the advantages and disadvantages of the two technologies compared. However, most of the Duel-comparisons are biased by - by paring one technology in its ascendence/descendence with one technology at its peak, - by selecting evaluation criteria which are favourable for the one partner - or by providing much more or better information on the one partner. La 5/7 versus Fw 190 is a great exception. The authors cover the whole 2,5 years during which these fighter-planes encountered in the skies over Eastern Europe, the make extensive use of literature from both sides and they provide numerous accounts from the pilots who flew and survived them. You get a very good picture on where the one plane type was good and on where the other. This booklet could serve as an example how the in-depth use of information from the former Soviet Union and from Germany might improve the quality of books on the Easten Front / The Great Patriotic War.