The Braves are trying to deal starting pitcher Jair Jurrjens. The Orioles want to bolster their starting rotation. Thus, Atlanta offered to trade Jurrjens to the O's - along with Martin Prado and a pitching prospect - in return for Adam Jones. And the Orioles said no. Was it a good call?
Jones is under team control for two more seasons. The past two seasons he's been at 2.6 and 2.9 fWAR, and calling him a three win player for his age 26-27 seasons doesn't seem unreasonable. There's the hope that he picks up his game and moves to the next level, but there are injuries and a drop-off in defense on the other side. That type of production would be worth around $31 M, but Jones will probably be paid only around $20 M in the two arbitration years. So that's ~$10 M in surplus value.
Jurrjens is about to turn 26, and is under team control for two more seasons as well. His 3.40 career ERA looks good, but his FIP (3.88) and xFIP (4.22) tell the tail of more of a middle of the rotation starter. Jurrjens K/BB ratio is only around 2, since he doesn't miss many bats (6.2 K/9 career, 5.3 K/9 last year) and his control isn't exceptional (3.1 BB/9 career, 2.6 BB/9 last year). He's been less of a groundball pitcher in recent years, but hasn't given up that many home runs (0.7 HR/9 career) - which I wouldn't expect to continue pitching in Camden Yards against the AL East teams. Same thing with the career .280 BABIP.
On top of the performance vs. peripherals disparity, Jurrjens has also been injured the past couple seasons, starting a total of only 43 games at the big league level. His fastball velocity fell off from 91-92 mph to just 89 mph in 2011. Given that the Braves seem somewhat anxious to trade him, I'd be a bit cautious. If he stays at the same level of production that he was at in '10-11 (1.2 and 1.5 fWAR, respectively), then he'd probably bring in only $5 M or so of surplus value.
Prado, ago 28, lost his second-base job to Dan Uggla last year. Like Jones and Jurrjens, he has two years of team control left. The .293/.341/.434 career hitter had a less than stellar 2011 as his BABIP fell to .266 (as his rate of line-drives dropped off), and without many walks (he's started to chase more pitches out of the zone, but isn't bad about it - he just makes so much contact he doesn't get into as many deep counts) or a ton of pop (double-digit homers and some doubles) he needs to hit for average to be a plus at the plate. If Brian Roberts can't play, Prado would probably move back to second for the O's. He has a career -8 UZR/150 at the position, though it was only around -3 runs recently (and he's at +3 career at third). Assuming his bat bounces back, Prado could be a 3-ish win player for the Orioles. Going with a more conservative 2.5, he'd have around $8 M in surplus value.
So right there, the O's have a decent chance of coming out even or ahead in the trade. The identity of the pitching prospect wasn't revealed, but I'd wager it wasn't one of the Braves' top young arms. Given that, I don't see the point of the deal for Baltimore. The only player they'd get who is scheduled to be around in 2014-2015 is the unknown pitcher. The point of dealing Jones is that he's getting closer to free agency, and the O's would still be in the same position with Jurrjens/Prado (who might be better than Jones on average, but I think carry more risk with similar high end). If the team is really going to trade Adam Jones, they need to shoot for at least one top prospect with more younger* players sprinkled in. That the O's turned down the offer** isn't bad news, as it would have been like a repeat of the Koji Uehara trade - picking up value, but not doing much to help the team contend (in the short or long term).
* Sure the team could flip Jurrjens/Prado for prospects, but I'd want that second deal in hand before trading Jones.
** Apparently, this exact offer wasn't made. The Orioles instead asked for Jurrjens, Prado, and two of the Braves' better pitching prospects which (a) would puts more emphasis on the correct area and (b) is kind of crazy (and so Atlanta said 'no'). Let them keep Jurrjens then, by all means - I'd want the prospects, and Prado if he'd come cheap (or not - another younger player is fine too).