Handlebar stem : height vs length I want to decrease the reach of my handlebars.
Does it matter whether I increase the height or get a stem with a smaller length(extension?) on my bike?

And is there any way to calculate the relation between the two? Something like, a 1 cm increase in height is equivalent to a 1.5 cm increase in length?

Background : I have an old single bolt handlebar stem(see image) with it's minimum insertion not visible(if it ever had one). When I raised it enough for it to be somewhat comfortable it started creaking every time I put power while pedaling or while climbing off the saddle.
I have another similar stem that is slightly more than 1 cm longer but has it's minimum insertion about 3 cm higher than what the current one does not creak at. I want to know whether it will really reduce the distance I have to extend forward. Yes seems to be the intuitive answer but I really want to know for sure because these are a big bother taking off and putting on.

Edit : The handlebars I mention are drops on a road bike.The horizontal portion is parallel to the ground
The answer is trigonometry. Most bikes have a headset angle of about 74°, give or take a degree. Over the adjustment range you're looking at that degree doesn't make a difference. 

Here, tan(74 degrees) = height change / reach change = ~3.5. So to get a centimetre of reach change to need to lift the stem 3.5cm, putting the stem up reducing the reach. Or you can invert that and say each centimetre you lift the stem changes the reach by about 3mm.

Roughly, the stem that's about 1cm longer but 3cm higher will have the same reach. But 3cm higher will feel quite different, and because of the way your body curves to reach the bars it will probably feel as though the reach is shorter.