"2nd hand low", "3rd hand high" and "splitting honeurs" as (so called) guidelines have nothing to do with table position or trick count, they just apply to you, when you (as a defender) are in the certain situation. For example, "2nd hand low" does apply to you as west, when south leads up to north, and it may apply to east (a few tricks later), if north leads up to south. But, please do not follow these guidelines blindly (like a roboter). Bridge is a complicated game and especialy defense is the hardest part of it. There are many situations, where the "2nd hand low" guideline wants you to play a low card, but the winning defensive play would be to play "2nd hand high", i.e. to prevent your partner from beeing endplayed a trick later or to save partner`s entry(, if, defending a nt contract, his long suit is not established yet). The same must be said regarding "3rd hand high" and "splitting honors". Try to learn to work out, what is going on among all four hands. This will improve your defense.