The search for the 'best' pair reveals a deeper tension: traders want predictability, but markets exist to transfer risk, not to offer free predictability. A pair that becomes widely known as 'easy to trade' attracts more participants, which in turn erodes the very patterns that made it easy. The most tradable pair today may be the most crowded trade tomorrow. This reflexive loop means the 'best' pair is not a static property of the market but a moving target shaped by collective belief.