Coming off of a Championship win in my 2029 PSFL season, as well as my 2nd season ever in a DDS game, I wanted to share some tips to help get newer GMs up to speed to being competitive in MP leagues. I found a lot of team building strategies through testing in offline single player that shed light on what ratings seem to make the biggest impacts on which positions, as well as what plays work and what don't. Implementing these strategies, the PSFL Jaguars went from a 4-13 team when I took them over, to going 15-2 in the 2029 regular season as well as winning the Super Bowl.
1) The MOST important thing is playbooks - For offense I would highly recommend starting with one of the playbooks here:https://drive.google.com/drive/folders/1paxMA92nxXaKMwloCmk1K83MQsOppvLz as they consist of the best plays for a full team of average rated players. From there you can adjust frequencies and try adding new plays and see how they perform. On defense it's a lot more trial and error since the game doesn't give a lot of data outside of watching games to assess play performance, however, it's generally best practice to limit your usage of 4 DB formations (unless you can reliably anticipate a run), as they can easily get blown up by the pass.
2) Player Rating Importance - For most positions, ignore OVR. The calculation for in game OVR isn't documented anywhere to my knowledge, but it appears to put more emphasis on ratings that have little to no impact on performance on most positions. OVR is also correlated to the general cost of players, so while a high OVR player may actually have all the right ratings they need (and many they don't) they will come with a higher price tag, which means cap space for depth, or player's who require a high OVR to perform well. Most high performing GMs will have a majority of their players ~70-80 OVR. I would only consider two positions for an exception to this rule: RB and QB. With a QB at high OVR you get versatility between the short and long game so you can perform well using balanced passing preference. For an RB you ideally want to have very high agility/speed/strength and generally this can only be found at high OVRs.
Here are the ratings, ranked in order of importance, that I build my team around.
QB - INT,ACC/ARM (SPD/AGI depending if he's a running QB),STR - If you're primarily going short you should focus on INT and ACC. With a long game you want to have a decent amount of STR (>40 if possible) as this will reduce risk of fumbles if he gets sacked and INT/ARM. For a running QB high STR is a must (>50)
RB - SPD,AGI,STR - SPD and AGI will effect rushing performance, STR will prevent fumbles.
WR - SPD,HNDS,AGI - SPD is king on WRs, and hands seems like the main determination for fumbles and has a very minor impact on catch rate from my testing. I think you really only need AGI if you're going short game with WRs. Be on the lookout for the "Deep threat" tag if you plan on going long. In testing I didn't see a notable difference in performance from a "possession WR" so it's not really a tag I try to go out of my way for.
OL - Weight,AGI,Pbl,STR - Weight is by far the most important stat on OL, prioritize this first and try to keep guys above 320 lbs. OL doesn't seem to have much impact on run game (so much so I put my backups in on run plays). Be on the lookout for the Tenacious/Athletic blocker tags, as they provide a large bonus to blocking ability. This is a position I personally would never go >80 OVR for since weight doesn't factor into the OVR calculation.
TE - SPD,HNDS,AGI, Weight,Pbl - I think these have more equal importance on TE than WR. Also depending on whether you go blocking TE or Recieving you're goign to build them more like a OL or a WR
Defense is a lot harder to guage IMO, it seems like a lot of it comes down to hitting "thresholds" based upon the guy they're covering. Take all of this with a grain of salt
DL - Weight ,STR, SPD, TCK - You want big guys on the DL. I noticed at RDE big strong guys seem to do better and at LDE faster guys performed better. This was tested using 2 different players so there could be some other stuff going on
LBs - SPD, STR, TCK - speed seems to be king on LBs. I like to have strength 55+, but higher is better for causing fumbles, and tackling I shoot for 60+
DBs - STR,SPD,TCK - the thresholds for CBs and S's vary, but generally this is the order of importance from my testing. This isn't to say focus 100% on strength and let speed fall to the wayside - the farther below a threshold you are
with the impact for being below threshold being roughly the order I listed the ratings in.
SKILL - Generally on non-line positions you want skill as high as you can get, but around 60+ is generally "good enough" as a starter, for line positions I shoot for 40+ as a starter, once you get above 60 there isn't really much benefit
Other helpful resources:
MP Playbook database: https://drive.google.com/drive/folders/1nkUfy3G36OzAO9MrLrYvKcAT_bJ32s7a