To show I can still play after so many years, my concentration level might go down.

The concentration level before a game is much higher, I think.

"If you take all that into account, you've had a very high level of concentration for a long time."

However, the concentration levels are so small that eating the fish is not considered a health risk.

She had seen that level of concentration in only one other man, Tucker.

Given his level of concentration, it startled him, but only for a moment.

We seem to play better and our level of concentration seems to be higher.

"Maybe that raised the concentration level to bring the pitching I had today."

I see different levels of concentration and effort in practice.

His level of concentration had been so great he'd not sensed her presence.