{"id":17302,"date":"2019-07-23T01:21:04","date_gmt":"2019-07-23T01:21:04","guid":{"rendered":"https:\/\/www.lifeandnews.com\/articles\/?p=17302"},"modified":"2019-07-24T04:55:24","modified_gmt":"2019-07-24T04:55:24","slug":"whats-really-behind-baseballs-home-run-surge","status":"publish","type":"post","link":"https:\/\/www.lifeandnews.com\/articles\/whats-really-behind-baseballs-home-run-surge\/","title":{"rendered":"What&#8217;s really behind baseball&#8217;s home run surge?"},"content":{"rendered":"<p><a href=\"https:\/\/theconversation.com\/profiles\/brian-j-love-775898\">Brian J. Love<\/a>, <em><a href=\"http:\/\/theconversation.com\/institutions\/university-of-michigan-1290\">University of Michigan<\/a><\/em> and <a href=\"https:\/\/theconversation.com\/profiles\/michael-l-burns-775903\">Michael L. Burns<\/a>, <em><a href=\"http:\/\/theconversation.com\/institutions\/university-of-michigan-1290\">University of Michigan<\/a><\/em><\/p>\n<p>At the 2019 Major League Baseball All-Star Game, Houston Astros pitcher Justin Verlander <a href=\"https:\/\/deadspin.com\/justin-verlander-says-mlb-is-juicing-baseballs-to-goose-1836199057\">griped<\/a> that too many home runs had been hit so far this season. He accused the league of altering, or \u201cjuicing,\u201d the balls, making it easier to hit home runs.<\/p>\n<p>Among players and fans, Verlander\u2019s \u201cjuicing\u201d claim has gained momentum.<\/p>\n<p>There\u2019s no question that there\u2019s been a home run surge. Home runs per plate appearance is currently sitting at 3.5%, an <a href=\"https:\/\/www.baseball-reference.com\/leagues\/MLB\/bat.shtml\">all-time high<\/a>. At this rate, players will hit more than 6,600 homers by season\u2019s end, shattering the prior record, <a href=\"https:\/\/www.si.com\/mlb\/2017\/09\/19\/most-home-runs-one-season-record\">set in 2017<\/a>, by more than 500 home runs.<\/p>\n<p><iframe loading=\"lazy\" id=\"v4ocu\" class=\"tc-infographic-datawrapper\" style=\"border: none;\" src=\"https:\/\/datawrapper.dwcdn.net\/v4ocu\/1\/\" width=\"100%\" height=\"400px\" frameborder=\"0\"><\/iframe><\/p>\n<p>Though league officials denied, for years, that they were altering the balls to boost the home run rate, <a href=\"https:\/\/www.washingtonpost.com\/news\/sports\/wp\/2018\/05\/24\/mlb-finally-admits-changes-to-ball-itself-fueled-home-run-spike-but-doesnt-say-how-or-why\/?noredirect=on&amp;utm_term=.c43f7bdfc5be\">last year they admitted<\/a> that the ball had changed, though they blamed suppliers. Then, earlier this season, <a href=\"https:\/\/foxsportsradio.iheart.com\/content\/2019-06-24-mlb-officially-acknowledges-the-baseballs-are-different-this-season\/\">they admitted that the ball\u2019s core had been changed<\/a>.<\/p>\n<p>We recently wrote a book titled \u201c<a href=\"http:\/\/www.corkedthebook.com\">Corked: Tales of Advantage in Competitive Sports<\/a>,\u201d so this topic is in our wheelhouse.<\/p>\n<p>It certainly seems that recent changes to the ball are playing a role in the uptick in home runs. But could other factors, like the climate and advanced analytics, also be to blame?<\/p>\n<h2>Breaking down the baseball<\/h2>\n<p>Rawlings makes around <a href=\"https:\/\/brokensecrets.com\/2011\/05\/25\/pro-baseball-teams-use-900000-balls-each-year\/\">1 million baseballs<\/a> each year for use in MLB play.<\/p>\n<p>Official baseballs consist of <a href=\"https:\/\/fivethirtyeight.com\/features\/juiced-baseballs\/\">six different materials<\/a>: a rubberized cork center (called a \u201cpill\u201d), two hemispherical clamshells of molded black vulcanized rubber, a layer of red rubber, wound wool, two flaps of cowhide leather, and 88 inches of hand-stitched, wax-coated red thread.<\/p>\n<p><a href=\"https:\/\/fivethirtyeight.com\/features\/juiced-baseballs\/\">There is a growing body of evidence<\/a> that, beginning around 2015, there have been distinct changes in the density and chemical composition of materials making up the league\u2019s official baseballs.<\/p>\n<p>The most noteworthy changes have been to the ball\u2019s core and surface.<\/p>\n<p>A 2016 investigation conducted by <a href=\"https:\/\/fivethirtyeight.com\/features\/are-juiced-balls-the-new-steroids\/\">FiveThirtyEight<\/a> found that official baseballs were bouncier and less air resistant beginning in 2015.<\/p>\n<p>Using X-ray imaging, FiveThirtyEight\u2019s study compared balls made prior to 2015 with those produced after. It found an average 40% decrease in core density in baseballs produced after 2015. Compositional analyses identified roughly 7% more rubber and 10% less silicon in the later pills. These changes correspond to lower pill mass and increased bounce.<\/p>\n<p>Nearly two years after the FiveThirtyEight investigation, Major League Baseball released its own <a href=\"http:\/\/www.mlb.com\/documents\/7\/9\/4\/278128794\/Full_Report_of_the_Committee_Studying_Home_Run_Rates_in_Major_League_Baseball_052418.pdf\">84-page report<\/a> acknowledging there were aerodynamic changes in the baseball \u2013 specifically, the balls were smoother. But the league claimed this wasn\u2019t due to any changes in the way Rawlings was making the ball. MLB suggested that it was likely due to slight variations in the materials used by Rawlings, along with the way the balls were being stored.<\/p>\n<p>For example, since Rawlings acquires its leather \u2013 and doesn\u2019t process it at its facilities \u2013 it\u2019s possible that an alternative tanning process could result in even smoother leather surfaces. Baseballs with smoother surfaces will, once hit, move through the air more easily. It\u2019s a minor change, but it matters.<\/p>\n<p>There is also the ball\u2019s thread. Journalists for the online sports publication The Athletic <a href=\"https:\/\/theathletic.com\/381544\/2018\/06\/06\/how-one-tiny-change-to-the-baseball-may-have-led-to-both-the-home-run-surge-and-the-rise-in-pitcher-blisters\/\">deconstructed baseballs<\/a> and found that laces in the newer ones \u2013 specifically those used to stitch seams on the 2016 and 2017 balls \u2013 are 9% thicker than those from 2014.<\/p>\n<p>The investigator speculated that the thicker laces might make it easier, when constructing the ball, to build a tighter ball that won\u2019t be impeded by as much air resistance when it\u2019s hit.<\/p>\n<h2>Climate controls<\/h2>\n<p>Then there\u2019s one explanation outside the control of the league, players or manufactorers: the climate.<\/p>\n<p>Cork in the pill is commonly harvested from the bark of the Cork Oak Tree in southern Europe and North Africa. But <a href=\"https:\/\/www.sciencenews.org\/article\/wine-corks-may-owe-quality-gene-activity\">a changing climate in these regions<\/a> has some concerned that cork quality is declining. Wine manufacturers are already <a href=\"https:\/\/winefolly.com\/tutorial\/alternative-wine-closures\/\">searching for<\/a> alternatives for making wine corks. While wine makers care about the cork\u2019s ability to seal, baseball makers are more concerned with the mechanical response of the cork in the ball.<\/p>\n<p>Baseballs are produced from a formed <a href=\"https:\/\/www.scientificamerican.com\/article\/inside-baseball-what-gives-a-baseball-its-bounce\/\">rubberized cork<\/a> that\u2019s engineered from smaller cork particles; but it\u2019s certainly possible that, like wine corks, their purity and composition are changing with the climate.<\/p>\n<p>The presence of humidity in and on the ball also affects its inertia and deadens its response when hit by a bat. In 2018, <a href=\"https:\/\/tht.fangraphs.com\/some-physics-of-humidors\/\">CBS reported<\/a> that Major League Baseball would require all teams to use air conditioned rooms to store baseballs in 2019. Most common HVAC systems not only lower the temperature in a room but also reduce the humidity. It\u2019s possible that controlling a ball\u2019s humidity through HVAC in muggier ballparks is actually increasing its liveliness by drying them out.<\/p>\n<p>Altogether, <a href=\"https:\/\/deadspin.com\/justin-verlander-says-mlb-is-juicing-baseballs-to-goose-1836199057\">Verlander\u2019s criticisms<\/a> may be warranted. Newer baseballs are more aerodynamic, probably in part due to a combination of smoother leather, lower profile stitches and a more accurate centering of the ball\u2019s pill, coupled with the way balls are being stored.<\/p>\n<h2>The analytics element<\/h2>\n<p>But there\u2019s another element to consider. What if hitters and pitchers are simply playing the game differently?<\/p>\n<p>Consider pitch speed. Pitchers that light up the radar gun have always been in vogue for the simple reason that hitters have less time to react to their pitches.<\/p>\n<p>How hard a pitch is thrown can influence how far a contacted ball travels. It\u2019s straightforward kinematics: Baseballs will bounce off the bat at a higher velocity when contacting a faster pitch.<\/p>\n<p>The average fastball velocity rose from <a href=\"https:\/\/www.postandcourier.com\/sports\/dangerous-trend-in-baseball-as-pitching-speeds-increase-so-do\/article_22670354-b5cf-11e8-934a-3b63e3a10c4b.html\">90.9 mph in 2008 to 92.0 mph in 2013<\/a>. But <a href=\"http:\/\/m.mlb.com\/statcast\/leaderboard#avg-pitch-velo,r,2015\">pitch velocity hasn\u2019t risen<\/a> during the most recent home run surge.<\/p>\n<p>So maybe it has something to do with the way hitters <a href=\"https:\/\/www.washingtonpost.com\/graphics\/sports\/mlb-launch-angles-story\/?noredirect=on&amp;utm_term=.ee648f5777de\">have changed their approach at the plate<\/a>.<\/p>\n<p>In recent years, they\u2019ve started to focus on what are called \u201c<a href=\"https:\/\/www.washingtonpost.com\/graphics\/sports\/mlb-launch-angles-story\/?noredirect=on&amp;utm_term=.ee648f5777de\">launch angles<\/a>.\u201d The <a href=\"http:\/\/m.mlb.com\/glossary\/statcast\/launch-angle\">launch angle<\/a> is the vertical angle at which the ball leaves a player\u2019s bat after being struck. Due to advances in analytics, it\u2019s become common knowledge that players have a much better chance of hitting a home run if the launch angle is <a href=\"https:\/\/www.washingtonpost.com\/graphics\/sports\/mlb-launch-angles-story\/?utm_term=.6e3f22859ddc\">between 25 and 35 degrees<\/a> and the ball bounces off their bat <a href=\"https:\/\/blogs.fangraphs.com\/exit-velocity-part-i-on-the-import-of-exit-velocity-for-hitters\/\">at a velocity of more than 100 miles per hour<\/a>.<\/p>\n<p>With such defined criteria for hitting home runs, <a href=\"https:\/\/www.sporttechie.com\/major-league-baseball-mlb-all-star-game-home-run-derby-hitting-launch-angle-exit-velocity-pete-alonso-ted-williams-tony-gwynn-wade-boggs-don-mattingly-montreal-expos\/\">it is no surprise that many hitters are tweaking their swings<\/a> accordingly. So while pitchers aren\u2019t throwing harder, the new focus on launch angles could be contributing to the recent home run surge.<\/p>\n<figure class=\"align-center \"><img src=\"https:\/\/images.theconversation.com\/files\/284789\/original\/file-20190718-116543-ctcrgf.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip\" sizes=\"(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px\" srcset=\"https:\/\/images.theconversation.com\/files\/284789\/original\/file-20190718-116543-ctcrgf.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=600&amp;h=434&amp;fit=crop&amp;dpr=1 600w, https:\/\/images.theconversation.com\/files\/284789\/original\/file-20190718-116543-ctcrgf.jpg?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=600&amp;h=434&amp;fit=crop&amp;dpr=2 1200w, https:\/\/images.theconversation.com\/files\/284789\/original\/file-20190718-116543-ctcrgf.jpg?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=600&amp;h=434&amp;fit=crop&amp;dpr=3 1800w, https:\/\/images.theconversation.com\/files\/284789\/original\/file-20190718-116543-ctcrgf.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;h=546&amp;fit=crop&amp;dpr=1 754w, https:\/\/images.theconversation.com\/files\/284789\/original\/file-20190718-116543-ctcrgf.jpg?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=754&amp;h=546&amp;fit=crop&amp;dpr=2 1508w, https:\/\/images.theconversation.com\/files\/284789\/original\/file-20190718-116543-ctcrgf.jpg?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=754&amp;h=546&amp;fit=crop&amp;dpr=3 2262w\" alt=\"\" \/><figcaption><span class=\"caption\">New York Mets rookie first baseman Pete Alonso connects for a home run on July 5. Alonso broke the Mets rookie home run record less than halfway through the season.<\/span><br \/>\n<span class=\"attribution\"><a class=\"source\" href=\"http:\/\/www.apimages.com\/metadata\/Index\/Phillies-Mets-Baseball\/4b57f825f6fd41e580fabc4a07160728\/47\/0\">AP Photo\/Frank Franklin II<\/a><\/span><\/figcaption><\/figure>\n<p>However, the emphasis on hard contact comes with a trade off. Players need to swing harder to achieve a higher exit velocity. The harder they swing, the more likely they\u2019ll be to hit one out \u2013 but that\u2019s if they make contact. Along with more home runs, the <a href=\"https:\/\/www.baseball-reference.com\/leagues\/MLB\/bat.shtml\">strikeout rate for hitters has skyrocketed<\/a>.<\/p>\n<p>So far this season, strikeouts per at bat is above 25% for the first time in league history.<\/p>\n<p>Whatever the reason for more home runs, are they good for the game?<\/p>\n<p>Sure, pitchers like Verlander might gripe, but you might expect fans to be ecstatic.<\/p>\n<p>If they are, it isn\u2019t being reflected at the gate. Even with more balls flying out of the park, <a href=\"https:\/\/nypost.com\/2019\/05\/30\/mlbs-attendance-problem-is-getting-worse\/\">attendance is at record lows<\/a>.<\/p>\n<p>[ <em>You\u2019re smart and curious about the world. So are The Conversation\u2019s authors and editors.<\/em> <a href=\"https:\/\/theconversation.com\/us\/newsletters?utm_source=TCUS&amp;utm_medium=inline-link&amp;utm_campaign=newsletter-text&amp;utm_content=youresmart\">You can read us daily by subscribing to our newsletter<\/a>. ]<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img loading=\"lazy\" style=\"border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;\" src=\"https:\/\/counter.theconversation.com\/content\/120265\/count.gif?distributor=republish-lightbox-basic\" alt=\"The Conversation\" width=\"1\" height=\"1\" \/><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: http:\/\/theconversation.com\/republishing-guidelines --><\/p>\n<p><a href=\"https:\/\/theconversation.com\/profiles\/brian-j-love-775898\">Brian J. Love<\/a>, Professor of Materials Science and Engineering, <em><a href=\"http:\/\/theconversation.com\/institutions\/university-of-michigan-1290\">University of Michigan<\/a><\/em> and <a href=\"https:\/\/theconversation.com\/profiles\/michael-l-burns-775903\">Michael L. Burns<\/a>, Clinical Lecturer of Anesthesiology, <em><a href=\"http:\/\/theconversation.com\/institutions\/university-of-michigan-1290\">University of Michigan<\/a><\/em><\/p>\n<p>This article is republished from <a href=\"http:\/\/theconversation.com\">The Conversation<\/a> under a Creative Commons license. Read the <a href=\"https:\/\/theconversation.com\/whats-really-behind-baseballs-home-run-surge-120265\">original article<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Brian J. Love, University of Michigan and Michael L. Burns, University of Michigan At the 2019 Major League Baseball All-Star Game, Houston Astros pitcher Justin Verlander griped that too many home runs had been hit so far this season. He accused the league of altering, or \u201cjuicing,\u201d the balls, making it easier to hit home [&hellip;]<\/p>\n","protected":false},"author":44,"featured_media":17299,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[293],"tags":[179,158,6698,502,1188,6700,6699],"_links":{"self":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/17302"}],"collection":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/users\/44"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/comments?post=17302"}],"version-history":[{"count":2,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/17302\/revisions"}],"predecessor-version":[{"id":17306,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/17302\/revisions\/17306"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media\/17299"}],"wp:attachment":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media?parent=17302"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/categories?post=17302"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/tags?post=17302"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}