We all know Pros play with high tension to prevent the strings move and get the best control. I see some racket's string pattern are rectangles(JS10) and other are perfect square. I have a JS10 and NR 800. I feel that perfect squares(NR800) improve accuracy. What do you think?
That's like saying "we all know pro's use glue to make sure the racket doesn't slip out of their hand". It's just based on nothing. Higher tension is to improve control, not to stop slipping. Slipping isn't optimal, but I found stencils with some proper stencil ink reduces the slippage a bit. To answer the squareness question: I'm not sure. The difference is pretty small, and I'm not sure if the shuttle would contact more horizontal strings than on the other racket. Or is the idea that the more weaving there is, the more tension the stringbed has? All in all, not sure if trolling My first thought was your question would be about the stringer aligning the strings perfectly during stringing, instead of after (that does make a difference!)
no. they are supposed to be rectangular. mainly because the racket is a egg shape. the elongated shape means that it is weaker and more compressible in the cross dimension than the mains dimension. if the main/cross strings have the same spacing, then the average tension density will be the same and the racket will have uneven pressure. having lower cross density compensates for that.
If out of 100 same strokes, you can aim exactly the same point each time with 1% of error then maybe it could be relevant. Else, improve your control/technics Rackets and strings do matter but only to some extend