I read some articles say you should hit your second serve even harder than the first serve, but with a lot more spin, but when I do that, my second serve consistency goes down. I can hit with probably 80% to 90% of my power and impart spin to kick my second serve in. I wanna hear expert's opinion on this. Also do you guys change grip on second serve? I use Continental grip on my first serve and strong continental on my second serve.