[paulcole]

The article really bungles the strategy talk. In the actual game, there are 14 tiles unseen.

http://www.cross-tables.com/annotated.php?u=22368#17

If Wellington plays his 86 point bingo, he empties the bag and if Lewis bingos back, the game ends and he'll get the value of Wellington's final rack added to his score. By not emptying the bag, Wellington keeps control of the game and prevents the only way he can lose.

It's not some crazy strategy, it's a pretty clear decision for a high level player.

Source: Played tournament Scrabble and memorized something like 50k words for about 4-5 years.