My premise is should be simple for everybody to grasp ; The mutual problem caused by Coors Field is lack of movement on pitches here. Hitters have a difficult time adjusting to greater movement of pitches away from Coors. Pitchers risk injury both physical and mental trying to compensate for the lack of natural movement at Coors. Not addressed by the media is the probable problems catchers have adjusting their framing after a series at Coors. It 's all about the movement.
Spitballs create asymmetrical drag on the ball by placing a small amount of moisture on a portion of the ball. The amount of moisture , the area covered and the type pitch thrown all effect the movement both in quantity and direction. Other factors are the relative humidity , air density , the viscosity , and the drag coefficient of the " lubricant " used. Some of the " artificial applicants" actually work by reducing the drag on the portion of the ball covered ; as opposed to increasing drag with others. The variety of substances used historically and their effects could fill several posts.
The most common use of the spitball was in making the common two seam fastball act like a forkball or split finger fastball. Spitballs have also been used as sliders and screwballs by creating greater than normal vertical and lateral break. Some experimentation has also been made on changing the depth of the break in the zone with curveballs.
By this time you are probably screaming that spitballs are illegal. That is currently so. It wasn't always so. Spitballs used to be legal. As a matter of fact a pitcher was enshrined in the Hall of Fame who learned the art of throwing it decades after it's illegality. Am I advocating cheating? Absolutely not ! Hear me out.
It is not to MLB's advantage to have a park like Coors that behaves so differently from all others. MLB recognized that when it allowed the installation of the humidor. While the humidor did marginally change the character of Coors ; it's been a failure in bringing Coors to reasonable parity with the rest of MLB. The real problem has been lack of movement at Coors and it's collateral damage it causes. I propose MLB legalize the spitball to all pitchers of every team at Coors Field only. The purpose would be to partially restore the movement on pitches lost here.
The advantages to MLB would manifest in these ways. Having movement restored would prevent pitchers risking injury by trying to throw with greater force to create movement. That would protect the investment of all teams in their pitchers. Having movement restored would prevent post Coors slumps by all hitters for all teams. By having Rockies hitters in particular not have as great an adjustment to make would increase competitiveness of the franchise and and greater interest in this market. It's a dollar motive to the benefit of all MLB.
MLB regulating the application and substances used could be an ongoing physics experiment to promote both the game and education in math and science. Trying to find a substance that would evaporate completely by the time the ball hits the catcher's mitt , for example , so the ball fields true would be but one example.