The letter 't' is one of the most common consonants in English. Looking at the pattern ___e__, many common 6-letter words with 'e' in the 4th position have 't' in them (like "select", "direct", "detect", etc.). Since I've already used vowel 'e' successfully and 'a' unsuccessfully, a high-frequency consonant like 't' gives me a good chance of finding another letter.