We’ve reached the Major League All-Star break, and the standings are taking shape. First-half overachieving teams are no longer surprises, they are good teams. Underperforming players are no longer in slumps, they are having bad seasons.
With 100 games’ worth of information off which to base projections, Vegas oddsmakers can more accurately set lines post All-Star break. We can use this accuracy against them, however, if we can detect strong trends that defy the odds.
I’ve looked over the numbers and have highlighted a few of the more prominent post All-Star break betting trends that have emerged over the past decade. Take a look:
This little trend is a personal favorite of mine because it jump starts your second half with a profitable Day 1. It seems that good teams benefit quite a bit from days off because favorites have played exceptionally well over the past several years on the day immediately following the All-Star break:
| Year | Record | ROI |
| 2010 | 11-3 | 35.5% |
| 2011 | 9-4 | 17.6% |
| 2012 | 8-5 | 7.8% |
| 2013 | 9-6 | 4.3% |
| 2014 | 12-3 | 35.7% |
| 2015 | 8-6 | -0.3% |
| 2016 | 9-6 | 2.2% |
| 2017 | 9-4 | 23.3% |
As you can see, favorites are 75-37 with a 15.7% ROI since 2010 on this day. If you narrow the criteria and look only at favorites with winning records, the ROI becomes 19.7% for that same span.
This trend makes sense because when good teams are able to rest and set up their rotations, they are very difficult to beat. Also, good teams in playoff contention are likely anxious to start back up for the second half while teams in the basement might be going through the motions.
As the MLB season progresses, fatigue becomes an increasingly significant factor. For this reason, I believe that post All-Star break trends involving rest days are very legitimate. I will share a second trend with you – one that has been profitable each season since 2009!
I started by looking at home underdogs playing a divisional opponent after the All-Star break. I figured that bad teams might get fired up for a series with a playoff bound divisional foe and rise to the challenge. I found that there is no correlation until you add an important filter – the opponent must be coming off a rest day. With this adjustment, the numbers are remarkably consistent. If you avoid large underdogs (a line of 200 or greater), this trend has held true for nine years:
| Year | Record | ROI |
| 2009 | 10-9 | 18.2% |
| 2010 | 10-9 | 19.5% |
| 2011 | 6-7 | 5.1% |
| 2012 | 10-11 | 7.2% |
| 2013 | 6-5 | 16.5% |
| 2014 | 10-11 | 7.2% |
| 2015 | 10-8 | 29.7% |
| 2016 | 12-11 | 18.6% |
| 2017 | 9-10 | 5.5% |
It appears that good teams may come out a bit lethargic at home after a day off late in the season. This trend has been profitable every season since 2009, with a 15.2% ROI in that span.
Singling out one season, the sample size for these two trends is too small to determine anything definitive. When the trends repeat for several seasons, however, we can put faith in it. The second half of the MLB season is my favorite time to bet baseball. Take advantage of these trends and find your own edge to finish 2018 strong.
