Why are some locks easier to pick the wrong way?

[Eazy123]

I got a Master m5 and m15, and while I never met a Master lock I couldn't beat before, these two are a pain in my behind. However, if I pick them counter clockwise they're simple. Is there a reason for this? My guess is that I'm not fighting a spring ...

Also, am I right in assuming that to pick clockwise, I just need to reverse the binding order from picking counter clockwise?

[Robotnik]

I got a Master m5 and m15, and while I never met a Master lock I couldn't beat before, these two are a pain in my behind. However, if I pick them counter clockwise they're simple. Is there a reason for this? My guess is that I'm not fighting a spring ...

Also, am I right in assuming that to pick clockwise, I just need to reverse the binding order from picking counter clockwise?

Picking the opposite direction can -and usually does - change the binding order, meaning that some locks that are extremely difficult to pick one direction will practically fall open the opposite way. This doesn't necessarily mean there's a direct reversal of binding order, however. Plug bore size, bible bore size, driver pin diameter, and key pin diameter all factor in to determining binding order, and these variances in manufacturing tolerances bring about different picking conditions depending on which direction is tensioned.

[Eazy123]

Thanks for the info - is spring tension usually a factor picking counter clockwise, or is it fine to use the same tension both ways?

I managed to get the M5 open clockwise yesterday and it seemed like I didn't have to use much more tension, but not sure...