Welcome @100stars!
You absolutely can spend it on Strength if that is what you want. If you put all 50 TPE into Strength that would boost it to 71.
Here is the update scale and a player builder to help you if you would like to do something different though.
http://sim-football.com/playerbuilder.html
0-50 - costs 1 TPE to go up 1 point
50-70 - costs 2 TPE to go up 1 point
70-80 - costs 5 TPE to go up 1 point
80-90 - costs 10 TPE to go up 1 point
90-100 - costs 15 TPE to go up 1 point
Do you want me to just put your Strength at 71, or would you like to do something different?
You absolutely can spend it on Strength if that is what you want. If you put all 50 TPE into Strength that would boost it to 71.
Here is the update scale and a player builder to help you if you would like to do something different though.
http://sim-football.com/playerbuilder.html
0-50 - costs 1 TPE to go up 1 point
50-70 - costs 2 TPE to go up 1 point
70-80 - costs 5 TPE to go up 1 point
80-90 - costs 10 TPE to go up 1 point
90-100 - costs 15 TPE to go up 1 point
Do you want me to just put your Strength at 71, or would you like to do something different?