Obviously there's a lot of interest in getting us a new backup PG to replace the decrepit-but-still-somehow-here Steve Blake. So I've complied just about all of the relevant stuff publically available in one place to help you guys get a handle on who's available and what their strengths and weaknesses are.
The Vitals

1. First let's get you guys caught up on who is where. A pistons fan on reddit has been aggregating a bunch of mock drafts to get an idea of every player's consensus position, so I’ve organized the players by this ranking. Here’s the document if you want to see where everyone ranks in aggregate.
2. The Pistons have the 18th and 49th overall picks in this draft. As you can see, pretty much the only PG outside of our reach this draft is Kris Dunn.
3. I highlighted in green wingspans 5 inches longer than the player’s height in shoes to show the distinction between guys who are long (Baldwin, English, Dunn) and guys who just happen to be tall (David Walker, Alex Caruso). Highlighted in red are guys with wingspans within 2 inches of their height in shoes, i.e. guys with T-Rex arms.
Overall Offense

1. Josh Adams stands out as the biggest scorer in this class, followed by Cat Barber and Kay Felder. Adams also stands out for scoring on the second best efficiency in this class, behind only David Walker. Dejounte Murray has an incredibly poor TS%.
2. Kay Felder scores the highest AST%, while Marcus Paige sports the best TOV%. Caruso compounds his low scoring with the highest TOV%.
3. David Walker and Cat Barber both had extremely good Net ORtgs, but the real stand out it Ulis. It’s easy to get good net ratings when you’re the best player on your team by a mile, and the team offense falls apart without you. But Ulis was playing next to a ton of top notch players on a tournament team, and he still sported a massively better ORtg than the team average. Up until this point, only his A/TO has stood out in a good way, so this puts a number to what has people see in him.
4. It’s absurdly hard for a PG to have a worse ORtg than his team, but somehow Murray and Wallace managed to do just that. A point guard’s entire value almost exclusively comes from their offense, so these guys are really unlikely to be good NBA players.
Penetration

1. UAFG stands for unassisted made field goals at the rim per40 pace adjusted, excluding put backs and transition buckets. UAFG gives you an idea about how capable the prospect was at penetrating and finishing against set defenses. PGs who struggle to get to the rim and score struggle in the NBA, like Trey Burke, Kendell Marshall, Tyler Ennis, and Tyus Jones, among others, but a higher number here doesn’t guarantee anything. Dejounte Murray, Wade Baldwin and Tyler Ulis all have low UAFG despite all being likely first round picks, while Jackson and Dunn are perfectly adequate here.
2. A layup is the best shot in basketball (besides a dunk), but the first step is being able to get there. %FGA at rim tells us how much of a guy’s offense comes at the rim. Generally you want over 30% of a guard’s shots to be at the rim; lower than 25% and you have to worry. Isaiah Taylor and Gary Payton get to the rim at exceptional rates for PGs. Alex Caruso, Wade Baldwin, Dejounte Murray, and Tim Quarterman all take a solid% of their shots at the rim but don’t have high UAFG. A.J. English, Josh Adams, Yogi Ferrell and Melo Trimble have god UAFG despite low %FGA at rim.
3. The next step is to actually make those layups, and rimFG% measures how well a guy can finish. Over 65% is quite good, while below 55%, it becomes a concern that he’ll struggle worse against NBA centers. Trimble’s and Adam’s low %FGA at rim despite good UAFG is explained here, as both of them rate as good finishers. In contrast, Quarterman and Caruso finish well but still have low UAFG – this is because they are just low scoring guys. Isaiah Taylor is a poor finisher, so his high UAFG is a result of sheer volume. Wade Baldwin’s low UAFG is explained in part by his poor finishing. VanVleet and Paige are simply embarrassingly poor finishers.
4. Drawing free throws is a fantastic skill which translates very well the NBA and can really save guys who struggle in other areas of scoring. Psycho T basically makes a living drawing fouls. James Harden got .94FTA/2PA in college and it’s a critical skill to his scoring efficiency. Small-school terrors A.J. English and Josh Adams feature unholy free throw rates above 1, better than Harden. David Walker, Tim Quarterman and Wade Baldwin make up for their poor UAFGs with excellent foul-drawing. Caruso and Murray fail to make up for their poor UAFGs by posting terrible FT rates, and Gary Paton mystifies with his inability to get to the line despite his aggressiveness attacking the basket, as does Demetrius Jackson.
Jump Shooting

1. To get a more accurate picture of a prospect’s shooting ability, you should look at FT%, the % of 3s that are assisted, and career numbers from 3 and the line.
2. Gary Payton, DeJounte Murray and Tyrone Wallace all struggle from 3 and the line and thus will need to work to improve their jumpers. Isaiah Taylor is a total non-shooter but at least nails his free throws.
3. Kris Dunn, Alex Caruso and Tim Quarterman all had decent 3P%s this year, but none of them are particularly good from 3. Caruso was assisted on literally every made 3 and still shot mediocrely. Quarterman is poor from the free throw line and historically not a good shooter. Dunn struggles from the line and was assisted on nearly ever made 3.
4. Adams, Barber and Felder are all better 3 point shooters than their %s show because they both had to make the majority of their own looks.
5. Demetrius Jackson and Melo Trimble shot poorly from 3 despite being historically good shooters. Jackson took over as lead ballhandler for the departed Jerian Grant, and was forced to take a lot of 3s off the dribble instead of being spoon-fed looks, which explains his decline, while Trimble just suffered a massive inexplicable slump.
6. Overall, Ferrell and Walker should be considered absolute snipers, while Baldwin, VanVleet, Adams, English, Barber, Paige, Felder and Ulis should all be considered very able shooters.
Passing

1. Assists aren’t that critical here. The context is more important. David Walker, Marcus Paige and Dejounte Murray didn’t produce a lot of assists, but this was because they split ball handling duties with their teammates. However, Cat Barber and Josh Adams didn’t.
2. A/TO ratio helps us start to sort the floor generals from the combo-guards. The cut-off is roughly around 2 – above it you get the floor generals, below it you have the combo-guards. Only Murray and Josh Adams have worryingly low A/TOs. Tyler Ulis has his first standout statistic with a magnificent 3.57A/TO.
3. Kris Dunn has always had an issue with turning the ball over. All of the prospects with high turnover rates flagged here slide more to the combo-guard side than floor general, except Caruso.
4. Assist%/Usage rate is just another way to measure playmaking and see who’s a score-first vs. pass first guard. It’s no surprise that super-low usage guys like VanVleet and Caruso are at the top here, but Kay Felder stands out as a playmaker here despite carrying an enormous scoring burden for his team. Kris Dunn as well.
5. Demetrius Jackson’s AST/USG comes in lower than I expected. Given his relatively low assist number I feel this show’s that he’s a bit more of a score-first combo guard, which makes sense since he was playing off ball last season.
6. Car Barber comes in last here. Despite being a PG nominally he was certainly a black hole on offense given that he always had the ball in his hand.
7. Marcus Paige has a pair of numbers in the red, but don’t be fooled, he is very capable as a passer. That low assist rate is a function of his role on the team this season.
Defense

1. Steal rates are one of the better regular stat indicators of future NBA success. Over 2 is the ideal here for good guards, but over 1.5 is basically the minimum. Mike Conley, Chris Paul, Steph Curry, Kyle Lowry, Rajon Rondo and Marcus Smart all had around 3 steals per40 pace adjusted at least once in college for instance, while Russell Westbrook, Jeff Teague, Damian Lillard, Deron Williams, Patrick Beverley, Kyrie Irving, and Jrue Holiday broke 2 steals. Only John Wall, Derrick Rose and Isaiah Thomas failed to break 2 steals per40 once in college and made the all-star game recently. Naturally though, a good steal rate doesn’t ensure NBA success, and we’re not looking for a future all-star, we’re looking for a good backup. Kris Dunn, Gary Payton and Alex Caruso stand out here, while Fred VanVleet, Kay Felder and DeJounte Murray rate well. Everyone in the red here will not cut it in the end.
2. The big athletic guards stand out as rebounders here: Dunn, Payton, and Wallace. Tyler Ulis and Marcus Paige predicable struggled to get boards, being short and on teams with a lot of size and talent around them. The oddball here is Josh Adams, the mighty mite who got over 5 defensive rebounds per 40 despite measuring at just 6’2”.
3. Backing up the eye test, both Gary Payton and Kris Dunn have freakishly good Net DRtgs for guards. Their Net DRtgs are similar to KCPs, Marcus’ Smarts, Paul George’s and other elite perimeter defenders.
4. Ulis, Ferrell, Paige, Barber, Trimble, Jackson and Taylor all rate as quite poor defenders. Ulis somehow won SEC DPOY despite this. Otherwise, no real surprises, since all of these guys are fairly small. Josh Adams again bucks the trend of tiny guards however, with a DRtg nearly 2 points better than his team’s.
5. Some consideration should be given to the how good the team’s defense is, and how little impact guards usually have here. Jackson and Barber rate poorly despite being on awful defensive teams. Alex Caruso and VanVleet rate well despite being on excellent team defenses.