FWIW, some common observations from a HS coach's perspective... (yes, I realize there are exceptions)...
- The vast majority of HS coaches are very competitive (whether outwardly or inwardly) and do not like to lose. They take their wins and losses to heart.
- Coaching HS requires a very significant time commitment, usually for very little pay. One of the few rewards is to develop a program that the players (and coaches) can take pride in. This means, among other things, playing as well as you can in games. This means putting the nine players on the field that give the team the best chance to do so.
- On average, HS coaches have some level of experience that reaches the college level. In our area, it is very unusual for any of the HS programs to not have at least a staff member or two, usually more, that have some college experience or above. I have also been around a few HS coaches without college experience who are/were very good HS coaches. While playing experience doesn't necessarily translate into coaching effectiveness, the point is that most HS coaches are not the clueless idiots they are so often made out to be here on HSBBCoachbashingWEb. 
There is usually some solid background. They typically go through an interview process to assure that is the case.
- The coaches are with the players practicing three hours a day, five or six days a week for several months. They see, more than anyone, what skill sets, attitude and effort are being displayed by each player at the present.
- Most HS programs have multiple coaches on the staff and all will express, to varying degrees, their opinions on the talent level and fit of each player. While the HC has the final say, it is rarely without some influence of the observations of the other coaches. So, playing decisions are usually a collective decision by those working with the group every day.
- HS coaches DO face pressure if they don't win. Perhaps they don't face the same types of pressure as college coaches. But, if they don't win, admin will always be looking for better options. More so, if they don't win, there are far more disgruntled parents who demand the attention of the AD and principal and there is significant noise to encourage their ouster.
- Combining just these first several observations alone, the idea of playing Johnny over Jimmy because Johnny is someone's son or somehow otherwise "favored" or "one of their guys" for any reasons other than skill sets, proven success, attitude and effort is just comical to me.
- All parents, to some degree, will have rose-colored glasses when it comes to their own kids. They want the best for their kids and only want good things to happen for them. This is their job. If player 1 is better at A,B,C,D,E,F and G but player 2 is better at X, player 2's parents will focus on X. If player 1 is a much better offensive player but player 2 has the edge on defense, player 2's parents will focus on the defensive comparison.
- When player 2's parents discuss their son with player 9,10 and 11's parents and talk about player 2 being better at X, those other parents will often do the courteous thing and nod in agreement and sympathy, thus (often unintentionally) feeding the fire to the idea that player 2 is being cheated.
- Baseball is one of the most difficult sports when it comes to analyzing skill sets and projecting who is likely to perform the best in game situations. It is the sport that is most inclined to have armchair coaching from the stands and second guessing.
- As others have said, stats can be very tricky in HS baseball. While they usually eventually tell an accurate story, this is not always the case. Beyond the small sample size issue - Most bench players will get opportunities to play only against inferior opponents. As a result, it is not uncommon for them to have better numbers than starters. This is a common source of parent complaints. Even when every player and coach on the team know there is no doubt that the starting player is better, the parent of the non-starter will argue that his/her son has better numbers and, therefore, must be better or at least deserve a better chance. Old School's comment about the eye test is very valid.
- Better, more seasoned pitchers will get scheduled the tougher games. So, often, the next tier of pitchers will have better numbers because they are matched against lesser opponents. Same problem often arises here with parents. "Why is my kid not getting the playoff start?" "Why is my kid not in the rotation this week?" "Look at his numbers! It's pretty simple to see who's better!"
- Failure. Again, even when it is clear to players and coaches that player A is better than player B, if player A is struggling, hitting only .200, losing games on the mound, etc., parents of player B cannot understand why their son isn't playing instead. "He hit over .400 in travel. I know he would do better than player A. Why is he not even getting a chance?".
- Coaches are often dealing with outside factors parents are unaware of... eligibility, illness, injury, attitude/behavior issues, etc.
- Coaches often factor in variables parents are unaware of ... matchups, hot hand, effects of other position moves, etc.
- Every coach (and parent) assigns different weight to different aspects of the game and it is a constantly moving target. There is give and take to almost all decisions. Do we need more offense or better defense at that position? More power or more speed? More experience or more athleticism? And often, more realistically, are his weaknesses likely to hurt us more or less than the other's weaknesses?
- Many parents and players get caught up with the thought process of "my son was always better than Jimmy, ever since T-ball". But, now, Jimmy is working out regularly and/or playing travel ball all year while Johnny is only playing baseball for the months of the HS season. The pecking order changes for the first time. Can be hard to accept or recognize for a parent.
- HS V is often the first time that many parents and players face the challenge of possibly not being one of the best nine. This can be difficult to deal with.
- "My son was the best player on JV". Quite often, an athletic player will have success at the JV level but swing mechanics are such that they will struggle vs. varsity pitching or their pitching stuff and approach will not succeed against varsity hitters. Coaches are trying to build a team that can defeat their toughest opponents, not just one that will win against inferior teams.
- HS V is often the first time that the structure is such that not everyone plays in most games. This can be tough to deal with and one common reaction is to question why they are not getting more playing time. This starts the cycle.
- For many players, they usually have a reasonably realistic view of where they stand talent-wise among the group... until they get home and parents start feeding them a steady diet of "you're better than Jimmy, you should be playing... ".
- It is human nature as spectators to play armchair quarterback and question decisions. X 10 when your team is losing. One of my favorite pastimes.
- It is my experience that maybe 5% of the time, there is actually a real question as to who should be playing and sitting on a given day. And, even then, there can be a strong case made for either choice. The other 95% falls under one of the perception issues mentioned above.
) but generally at the HS or college levels coaches will play the best players unless a player misconducted a lot. A coaches job security hinges on winning or losing and most HS coaches don't have that much talent that they can afford to sit one of the best players. Of course coaches have and ego and there are politics but in the end his job is to win and if he doesn't someone else will get the job.
