Jacob Aagaard wrote about Andersson in his book Excelling at Chess, stating: "He is a very prophylactic player, seeing all kinds of tactics well in advance and avoiding pitfalls with great skill."

For Ulf, who struggled to keep his nerves in check during over-the-board chess and often avoided lines with any risk of loss, it was a relief to have ample time to consider the subtle nuances of each move.

While in the process of winning in the 'Norwegian Postal Chess Federation – 50 Years' tournament, he attained the highest provisional rating in ICCF history, with a score of 2821 on the 1998 list.

[8] However, as postal play gave way to faster-paced email tournaments, he found himself having to send moves before feeling satisfied with them to avoid losing on time.

[12] In the following game, using the "hedgehog" formation he in part originated (characterized by a half-open c-file and pawns on a6, b6, d6, and e6, knights on d7 and f6, bishops on b7 and e7, a rook on c8, and kingside castling), Andersson inflicts upon Anatoly Karpov the latter's first loss as world champion: Bibliography