Updated: Jul 12, 2019
You see it all the time in baseball. The batter has a 3-0 count and the pitcher grooves the next pitch down the heart of the plate for strike one as the batter simply watches it go by. It is one of the "unwritten rules" of baseball - don't swing 3-0 when you are one more ball away from achieving a walk. Let's take a more detailed look at why 3-0 takes may be the wrong "unwritten rule" to live by.
If you haven't seen the twitter thread on 3-0 counts by Clyde Keller @clydekeller I highly recommend you check it out.
Coach Keller talks about some major points related to the 3-0 count. In summary, after looking at 3 years worth of game data fastballs were thrown 98% of the time in 3-0 counts and targeted mainly to the middle of the zone. Meanwhile 3-1 counts saw 75% fastballs targeted toward the outside portion of the zone. 3-0 counts also end up 3-2 counts 71% of the time.
Let's look at some more data collected by 6-4-3 Charts, an advanced scouting service in NCAA baseball/softball.
In the charts above, you can see batting average and slugging percentage for each count situation for all of NCAA baseball in 2019.
3-0 Count Batting Average: .421 vs 3-1 .377 vs 3-2 .215 3-0 Count Slugging Percentage: .739 vs 3-1 .610 vs 3-2 .318
According to the data, the 3-0 count yields some of the most productive and damaging results for the offense. If you are going to swing away 3-1, you should probably swing 3-0 as well. If 71% of 3-0 counts end up 3-2 there isn't much reason to give the pitcher strike one and make his or her job easier.
Typically, a 3-0 pitch is a fastball thrown with less effort and less velocity through the middle of the zone, which is definitely a good pitch to hit. Looking at the 6-4-3 data, each time the pitcher delivers a strike the chance of creating an out increases and slugging decreases. Hitters should be aggressive on pitches that are likely fastballs for strikes to maximize their odds for success and hard barrel contact.
What about being one pitch away from a walk? At higher levels of baseball, teams have good pitching and usually walk 5 or less batters per game. Pitchers can command multiple pitches, throwing strikes 60% or more of the time. A 3-0 take on a fastball middle that sends the count to 3-1 creates vulnerability for the hitter. Now the pitcher can attack with a better located fastball or an off-speed pitch. If the hitter misses or fouls the delivery, or maybe the umpire calls strike two, now the count is 3-2 and the hitter has gone from a plus advantage situation to a much more favorable situation for the pitcher.
Should hitters always swing 3-0? Not necessarily. Always swinging 3-0 is not any better of an idea than always taking 3-0. If there is a pitcher on the mound who has no command and consistently throws more balls than strikes, it may be a good idea to take 3-0. The idea of swinging 3-0 is to increase the chance for offensive success and the hitter has to be disciplined - not just free swinging because it is 3-0. That is not the purpose.
What about youth baseball or even some high school baseball where pitchers may not have tremendous command? I think it is even more important to remove the "take just to take" 3-0 mindset with younger hitters. This is a perfect opportunity to teach them to be aggressive and disciplined hitters on predictable counts. Young hitters can learn to drive the well-located fastball in the heart of the plate and take the missed location that may result in ball four. Let's be honest, the umpire's strike zone seems to mysteriously grow on 3-0 counts and the pitch anywhere near the plate usually leads to a 3-1 count anyway.
In summary, don't just see a 3-0 situation and automatically take. Don't handcuff your hitters and allow pitchers to lazily throw one in the zone like a free throw in basketball. Use good judgement and apply an advantageous strategy to the situation.
Hope this helps.
See you on the diamond.