Correct

摸头

/ mō tóu / 
Strokes

Example

As a Verb

[often used in negative construction] begin to understand; get to know sth

1
Wǒ
我
duì
对
wǎngqiúsài
网球赛
jìfēn
记分
fāngfǎ
方法
bù
不
mōtóu
摸头
  
。

I am at a loss as to how the score is kept in a game of tennis.