Welcome one and all to our first meeting of AA…Analytics Anonymous.  These weekly meetings are free for anyone to attend, and I promise we’ll have quality snacks to share.  AA is a support group here @Razzball to address all your fantasy baseball needs.  Your homework each week is to come prepared to contribute to the discussion topic and help others address their afflictions.  Fear, not my friends, 9 of 10 industry analysts approve of using baseball analytics to grow your fantasy baseball experiences.  We @Razzball are here to help.  Let’s lean on each other!

For the maiden AA meeting, we’ll have just a “speedy” session.  We’re going to talk stolen bases, and specifically SBO (Stolen Base Opportunity).

As the abbreviation implies, the SBO attempts to quantify the opportunity a player has to steal a base.  Since most SBs occur when a player steals second base, it is heavily dependent on how often the hitter reaches first base.  Therefore, SBO is calculated as:

SBO = (SB + CS)/(1B+BB)

Note:  The calculation doesn’t distinguish between success (SB) and failure (CS) to steal the base, just the number of attempts.  Likewise, extra base hits are not factored into the equation, just singles (1B) and walks (BB).

So, what is a good SBO and how can we use it to our advantage?

In my research, SBO isn’t one of the sexier analytics in use today.  These days, we typically look at Stolen Base Percentage (SB%) or simply the number of SB the previous year or in projections.  Maybe that’s good enough for most.  But when you’re looking for an edge, it’s worth taking some time to validate projections or to look for outliers.

An SBO of 20% (0.20) or more is a common threshold for identifying players to target.  Ultimately, we want players who not only have the OPPORTUNITY but also a high EFFICIENCY for achieving SBs.  So, instead of just looking at SBO or SB%, I will typically target players who meet both of my thresholds.

Let’s take a critical look at 2023 projections for some of the 2022 stolen base leaders.

The first thing that sticks out to me here is that the SB and SBO projections are generally similar for all players.  Therefore, the projections appear to not consider a higher SB% with the larger bases in 2023.  Perhaps that needs to be a longer discussion for another day.

Now, let’s look at how the 2023 projected SBs correspond to the 2022 totals and 3-Yr Ave SB%.

Projections for Cedric Mullins and Marcus Semien appear to be in very good alignment across the board.  For everyone else, questions abound.

Let’s start with Randy Arozarena.  Remember, I mentioned OPPORTUNITY and EFFICIENCY.  Here we see Aronzarena’s opportunity is projected to remain consistent.  Similarly, his SB% of 73% is generally consistent with his 3-Yr Ave.  However, we see a projected drop in SB in 2023 by about 10%, even with the larger bases in 2023, so something else is going on here.

Next, Tommy Edman.  Note his SB are projected to drop a bit despite a slight increase in projected SBO and coming off an excellent SB% in 2022.  So, despite the projected increase in opportunity, the prognosticators clearly feel his SB% will regress toward the 3-Yr Ave.

On the flip side, Kyle Tucker’s 2022 SB% was under his 3-Yr Ave.  So, the miniscule drop in projected SB suggests the same prognosticators feel his SB% will continue to regress from the 3-Yr norm and be more in line with his 2022 rate.  I’m not sure I’m buying that logic yet.

Trea Turner is sort of an enigma here.  The new Philly SS is expected to see an increase in opportunity but a slight drop in efficiency from his 2022 SB% of 90%.  Are NL East catchers better at throwing out baserunners than in the NL West? I’m not buying this one either.  Increased opportunity, plus a few inches closer between bases, should result in a bump in SB numbers to me.  He’s already a consensus Roto top 3 pick so I don’t think this changes much, but I’ll sleep well projecting the over everywhere I have him.

Lastly, let’s take a deeper dive into Jake McCarthy.  With consistent SBO and SB% in the table, but an almost 40% bump in projected bags, we need to peel the onion back to understand this projection.

McCarthy spent time bouncing between AAA and the Diamondbacks, logging a total of 99 games (321 ABs) with the parent club.  His 2023 projections suggest 147 games (558 ABs).  With a sprint speed in the 98th percentile, nobody disputes his ability to achieve another 87% SB%.  So, do the additional 237 ABs account for the 40% bump in SBs?

Actually, no! Take a look at the table below, calculating his SB per AB rates.

Don’t go looking for SB/AB in your handy-dandy Analytics reference, it isn’t really an official thing (yet?).  As I was looking into Jake McCarthy, I wanted to better diagnose if the projected increase in SB was strictly a result of the increase in ABs.  As you can see here, that is not the case.  In 2022, McCarthy was tallying SB at a rate noticeably higher than the 2023 projections estimate.

Remember, this guy has 98th percentile speed.  So, if we simply assume he’ll pick up a SB at the same rate per ABs as in 2022, his 2023 projections jump to 41.6 (ok, call it 42).  That’s 10 extra bases than currently projected.  Even if you have reservations about his hit tools or full season playing time, cut the difference and estimate 37.  Either way, I’m good.  The analytics are pointing to the OVER.


So, as we’ve seen here, SBO doesn’t appear to provide a true indicator of SB potential but it can be a useful measure to validate projections or identify anomalies that should be investigated further.  If you’re so inclined…


If speed is your thing, do yourself a favor and follow my buddy @marmosdad who now pens the weekly SAGNOF article here at Razzball.  He put up a nice primer on steals this week for your reading pleasure. (Get The SAGNOF Article Here)

Also, don’t forget to visit the Razzball rankings page (https://razzball.com/2023-fantasy-baseball-rankings/) for everything you need to prepare for upcoming fantasy baseball drafts.

Finally, share your comments below and be sure to come back next week for another Analytics Anonymous support group meeting (Topic TBD).