ER endings are common enough that players should take them seriously after an early E or R hit. The pair appears in ordinary nouns, comparatives, and agent-style words, so it can survive many first guesses even when other letters are eliminated.
The danger is overconfidence. A yellow E and yellow R do not automatically mean an ER ending. They can also point to RE, E-R gaps, or words where R sits in the middle. Confirm ER only when the position evidence supports it, then use high-coverage consonants such as T, L, N, V, F, H, and O to split the pool.
Frequency is a guide, not a shortcut. A common pattern can still be wrong if the positions do not fit, and a
less common pattern can become the best explanation once several high-frequency letters are removed.