[Deque]

I understood it that way and when I mentioned that some code would be nice, I didn't mean a function searching for a value in an array. That's something everyone can find with google.

I apprechiate the practical way of explaining this algorithm. But doing this manually is only the first step in understanding, if you really work on a problem like this you can go a step further and create your own script that does the binary search for you (everything else is cumbersome, a good hacker should have some lazyness when it comes to repeated tasks). So I think such a script would be a great addition to your tutorial.

Edit:

Then we try with 20. Again we get the same error. So it's between 1 and 20 as well.

50 / 2 = 25, not 20.
If you choose an arbitrary number you are not doing a binary search. Binary search always takes the element in the middle.

[RogueCoder]

I understood it that way and when I mentioned that some code would be nice, I didn't mean a function searching for a value in an array. That's something everyone can find with google.

I apprechiate the practical way of explaining this algorithm. But doing this manually is only the first step in understanding, if you really work on a problem like this you can go a step further and create your own script that does the binary search for you (everything else is cumbersome, a good hacker should have some lazyness when it comes to repeated tasks). So I think such a script would be a great addition to your tutorial.

Edit:

Then we try with 20. Again we get the same error. So it's between 1 and 20 as well.

50 / 2 = 25, not 20.
If you choose an arbitrary number you are not doing a binary search. Binary search always takes the element in the middle.

Yeah that's true. I use sqlmap normally, then some manual testing if sqlmap fails me. But sometimes I just like to do everything manually It serves two purposes. One, it keeps my knowledge sharp, Two, it kills time when I'm bored

I also fixed the error.. Changed 20 to 25 and 10 to 12

[MrGeek]

Well written tut mate
Binary Search is very useful in Boolean-Based SQLi