Tile tracking or 'consonant-heavy', how many S's or blanks are unseen, if an opponent is likely to have a bingo on their rack, or which tiles to play or conserve. For example, if Alice has the option of playing J(I)NN or J(I)LL, and four N's and zero L's remain unseen, then assuming both plays are otherwise equal (in terms of score, openings for the opponent), J(I)NN is likely the better play. Letter frequency lists for both Scrabble and Words with Friends are easily accessible (some versions of Scrabble have the tile distribution directly on the board) and, unlike word lists, using them
Challenge (Scrabble) has not seen a single drawn tile yet, in order to consider whether to challenge. To do this, the player simply announces, "Hold," which prevents the opponent from drawing replenishment tiles for 15 seconds (but may draw thereafter, keeping those tiles separate). The player may decide to rescind the hold, or challenge the play. Scrabble and Scrabble-like game sites on the Internet such as Yahoo! Games' Literati, Internet Scrabble Club and Lexulous offer automatic verification as an option, which makes it impossible to play an invalid word. The Facebook version of Scrabble and Zynga's mobile game Words With Friends make