Tuesday the 17th at noon is the deadline for teams and players to settle potential arbitration cases without exchanging formal arbitration figures between a player and the team. On Wednesday, once those figures are exchanged, this is where a team sees just how far apart they may potentially be with a player. Typically, many deals are worked out after that by meeting at some point in the middle of the two figures. For those negotiations that are hopelessly apart, arbitration hearings start February 1st and go until February 15th.
At the start of this offseason, the Pirates had 9 potential arbitration eligible players. But after non-tendering Ross Ohlendorf and trading Jose Veras for Casey McGehee (also arb-eligible), the Pirates were left with 8 players.