CR TIP of faster way /baduk/

Now, does it come under your notice?

It can be counted 5-eye-space-number. 8
Also you can count that 12 - 4 = 8.

It can be counted 4-eye-space-number. 5
Also you can count that 8 - 3 = 5.

It can be counted 3-eye-space-number. 3

Also you can count that 5 - 2 = 3.

If there are 2-in-crosses ( triangle marks ), it's same of 1 lower phase.

So, it can be possible below.

one way : 12 - 3 + 4 = 13
another way : 8 + 1 + 4 = 13

It may be a particular thing, and also it may save your time.

CR TIP of easier way /baduk/

Out-space-advantage-side is white.
So, imagine x marks are filled with any stones.
And, calculate only out-spaces, and you can read it faster.
In this case, white-out-spaces are 5, and black-out-spaces are 6.
So, black wins the race.
And, white has 9 ko threats. ( out-spaces 5 + in-spaces 4 = 9 )

Imagine like this.